This page describes the format of the icon stored at [[NCCH#CXI|CXI]] ExeFS:/icon and [[CIA]] icons.
The size of icons is 0x36c0 bytes. The CXI icon is displayed by [[Home Menu]] and [[System Settings]](3DS Software Management), while [[CIA#Meta|CIA icons]] are dummies and not yet utilised by Dev 3DS' (as of rev 47586).

== Format ==

{| class="wikitable" border="1"
|-
! OFFSET
! SIZE
! DESCRIPTION
|-
| 0x00
| 0x04
| Magic 'SMDH'
|-
| 0x04
| 0x02
| Version
|-
| 0x06
| 0x02
| Reserved
|-
| 0x8
| 0x2000
| 16 application titles structs, each 0x200 bytes
|-
| 0x2008
| 0x30
| Application Settings
|-
| 0x2038
| 0x8
| Reserved
|-
| 0x2040
| 0x1680
| Icon graphics
|}

== Application Titles ==

{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x00
| 0x80
| Short Description
|-
| 0x80
| 0x100
| Long Description
|-
| 0x180
| 0x80
| Publisher
|}

All encoded in UTF-16.
There are 16 app title structs(currently only 12 are used), each one for separate languages.

The languages by order of appearance:

* 1st: Japanese title name
* 2nd: English title name
* 3rd: French title name
* 4th: German title name
* 5th: Italian title name
* 6th: Spanish title name
* 7th: Simplified Chinese title name
* 8th: Korean title name
* 9th: Dutch title name
* 10th: Portuguese title name
* 11th: Russian title name
* 12th: Traditional Chinese title name

== Application Settings ==

Most of these flags are only used by the [[Home Menu]]. All of these are represented in SMDH files in little endian. But when documented below, the tables represent values in big endian.

{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x2008
| 0x10
| Region Specific Game Ratings (For use with Parental Controls)
|-
| 0x2018
| 0x4
| Region Lockout
|-
| 0x201C
| 0xC
| Match Maker IDs (Online Play)
|-
| 0x2028
| 0x4
| Flags
|-
| 0x202C
| 0x2
| EULA Version
|-
| 0x202E
| 0x2
| Reserved
|-
| 0x2030
| 0x4
| 'Optimal Animation Default Frame' (for BNR)
|-
| 0x2034
| 0x4
| CEC (StreetPass) ID (So the Home Menu knows which application icon to show the 'Green' CEC notification for)
|}

=== Region Specific Game Age Ratings ===

These flags tell the 3DS the 'Age Rating' of the software for the below regions:

{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x2008
| 0x1
| CERO (Japan)
|-
| 0x2009
| 0x1
| ESRB (USA)
|-
| 0x200A
| 0x1
| Reserved
|-
| 0x200B
| 0x1
| USK (German)
|-
| 0x200C
| 0x1
| PEGI GEN (Europe)
|-
| 0x200D
| 0x1
| Reserved
|-
| 0x200E
| 0x1
| PEGI PRT (Portugal)
|-
| 0x200F
| 0x1
| PEGI BBFC (England)
|-
| 0x2010
| 0x1
| COB (Australia)
|-
| 0x2011
| 0x1
| GRB (South Korea)
|-
| 0x2012
| 0x1
| CGSRR (Taiwan)
|-
| 0x2013
| 0x1
| Reserved
|-
| 0x2014
| 0x1
| Reserved
|-
| 0x2015
| 0x1
| Reserved
|-
| 0x2016
| 0x1
| Reserved
|-
| 0x2017
| 0x1
| Reserved
|}

Active ratings have a bitmask of 0x80, and inactive ratings have no bitmask at all. Ratings without the 0x80 bitmask are ignored. 0x40 bitmask indicates Rating Pending. 0x20 bitmask indicates No Age Restriction.
Age limits are set by adding the minimal age to 0x80 (for example, limiting to 12 years and up would give a bitmask of 0x8C)

=== Region Lockout ===

This u32 flag is what the Home Menu uses to determine the [[Home Menu#Region Lockout|Region Lockout]] of a title.

{| class="wikitable" border="1"
|-
! REGION
! BITMASK
|-
| Japan
| 0x01
|-
| North America
| 0x02
|-
| Europe
| 0x04
|-
| Australia
| 0x08
|-
| China
| 0x10
|-
| Korea
| 0x20
|-
| Taiwan
| 0x40
|}

Regions are 'included' in region lock by setting their bitmask value. Nintendo defines region free as 0x7fffffff. Early in the 3DS' development, Nintendo grouped the Australian and Europe markets together. Nintendo defines market Europe as having the combined bitmasks of Europe and Australia. No 3DS' which check the Australia bitmask have been seen (Australia uses the European 3DS model).

=== Match Maker IDs ===

These IDs are an application's online gaming IDs.

{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x201C
| 0x4
| Match Maker ID
|-
| 0x2020
| 0x8
| Match Maker BIT ID
|}

=== Flags ===
The u32 is used for storing flags as bit-masks.

{| class="wikitable" border="1"
|-
! FLAG
! BITMASK VALUE
|-
| Visibility Flag (Required for visibility on the Home Menu)
| 0x0001
|-
| [[Home Menu#Auto-Boot Kiosk Function|Auto-boot]] this gamecard title
| 0x0002
|-
| Allow use of 3D? (For use with parental Controls. An application can use the 3D affect, even when this flag isn't set)
| 0x0004
|-
| Require accepting CTR EULA before being launched by Home (see below)
| 0x0008
|-
| Autosave on exit? (see below)
| 0x0010
|-
| Uses an [[Extended Banner]]?
| 0x0020
|-
| [[SMDH#Region Specific Game Age Ratings|Region game rating]] required
| 0x0040
|-
| Uses save data? (see below)
| 0x0080
|-
| Application usage is to be recorded. If this is not set, it causes the application's usage to be omitted from the Home Menu's [[Home_Menu#Cache.dat & CacheD.dat|icon cache]], as well as in [[????????|other places]].
| 0x0100
|-
| Disables [[SD Savedata Backups]] for this title. This is in addition to [[NS CFA|the blacklist]].
| 0x0400
|}

====Effect of SaveData and AutoSave====

These options have no effect on the performance of the application itself: they're used to select an appropriate warning when closing an application from [[Home Menu|Home]].

* Both off: "Closing software" (no warning if quitting directly with X)
* SaveData: "Do you want to close [...]? (Unsaved data will be lost.)"
* AutoSave: ?
* Both on: "Saving data and closing software..." (no warning if quitting directly with X)

=== EULA Version ===
This is the EULA version which is checked when the Accept EULA flag is set, the version is compared to one stored in the 3DS. If the SMDH version is greater, then the user will be prompted to accept the EULA.

{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x202C
| 0x01
| EULA Version Minor
|-
| 0x202D
| 0x01
| EULA Version Major
|}

=== 'Optimal Animation Default Frame' (for BNR) ===

This is a float, indicating the preferred (or 'most representative') frame for the banner animation.

=== CEC (StreetPass) ID ===

This u32 represents the application CEC ID. This is likely loaded by applications for use with the CEC services as well.

== Icon graphics ==

At offset 0x2040, there are two icons:
{| class="wikitable" border="1"
|-
! START
! SIZE
! DESCRIPTION
|-
| 0x2040
| 0x480
| Small - 24x24 (shown on top screen when pausing the app)
|-
| 0x24C0
| 0x1200
| Large - 48x48 icon (the general icon)
|}

Both of the icons are encoded in RGB565 meaning 16bpp. Although both icons are known to be RGB565, developers have the option of encoding icons (and banners) with the following encodings :

* RGBA8
* RGB8
* RGBA5551
* RGB565
* RGBA4
* LA8
* HILO8
* L8
* A8
* LA4
* L4
* ETC1
* ETC1A4

This does not necessarily mean the other encodings will be used, it is just that those are the options when compiling. Like we've seen with Super Mario 3D Land Nintendo has changed save file encryption, and likewise they can encode icons and banners differently ''should they choose to''. Currently we've seen just RGB565 so don't be fooled if an icon doesn't show up right! It is probably one of these formats above. Although we will probably not see other formats used for a while it's nice to know they have an opportunity to change.

The data is encoded in tiles (starting from size 8x8, continuing recursively).

If the buffer is like this:

{| class="wikitable" border="1"
|-
! 0
! 1
! 2
! 3
! 4
! 5
! 6
! 7
! 8
! 9
! 10
! 11
! 12
! 13
! 14
! 15
! 16
|-
|}

Then the image would look like this:

{| class="wikitable" border="1"
|-
! x=0
! x=1
! x=2
! x=3
! x=4
|-
| 0
| 1
| 4
| 5
| 16
|-
| 2
| 3
| 6
| 7
| ...
|-
| 8
| 9
| 12
| 13
|-
| 10
| 11
| 14
| 15
|-
|}

== Tools ==

[[CiTRUS]] - (GUI)(Windows Only) Generating ICN files

[[3DSExplorer]] - (GUI)(Windows Only) Parsing ICN files

3DS Userland Flaws

2016-06-16T13:42:38Z

LiquidFenrir: /* Useless crashes / applications which were fuzzed */

This page lists vulnerabilities / exploits for 3DS applications and applets. Exploiting these initially results in ROP, from that ROP one can then for example try exploiting [[3DS_System_Flaws|system]] flaw(s).

=Non-system applications=
{| class="wikitable" border="1"
|-
! Application name
! Summary
! Description
! Fixed in app/system version
! Last app/system version this flaw was checked for
! Timeframe info related to this was added to wiki
! Timeframe this vuln was discovered
! Vuln discovered by
|-
| Cubic Ninja
| Map-data stack smash
| See [[Ninjhax|here]] regarding Ninjhax.
| None
| App: Initial version. System: [[10.4.0-29]].
| Ninjhax release
| July 2014
| [[User:smea|smea]]
|-
| The Legend of Zelda: Ocarina of Time 3D
| UTF-16 name string buffer overflow via unchecked u8 length field
| The u8 at offset 0x2C in the savefile is the character-length of the UTF-16 string at offset 0x1C. When copying this string, it's essentially a memory-copy with lenval*2, not a string-copy. This can be used to trigger buffer overflows at various locations depending on the string length.
* When value is >=0x6E it crashes when saving the saveslot, this causes a stack-smash however it normally crashes before it returns from the function which had the stack-frame overwritten.
* With value >=0x9A, it crashes via stack-smash in-game once any dialogs are opened(touching buttons on the touch-screen can trigger it too).
* Length value>=0xCD causes a crash while loading the saveslot, via a heap buffer overflow. This buf-overflow overwrites a heap memchunk following the allocated buffer. When the first 16-bits overwriting that heap memchunk is not the memchunk magic-number(0x7373), the mem-alloc code will just return a NULL ptr which later results in a crash. When the magic-number is valid, the mem-alloc code will continue to attempt to parse the memchunk, which may crash depending on the data which overwrote the memchunk. This heap code is separate from the CTRSDK heap code. Exploiting this doesn't seem to be possible: since the heap code actually verifies that the magic-number for the next/prev memchunk ptrs are correct(unlike CTRSDK), it's not possible to change those ptrs to useful arbitrary addresses outside of savedata(like with triggering a write to a c++ object ptr which later is used with a vtable func-call, this is what one would do with CTRSDK heap here).

On March 11, 2015, an exploit using this vuln was released, that one was intended for warez/etc. The following exploit wasn't released before then mainly because doing so would (presumably) result in the vuln being fixed. The following old exploit was released on March 14, 2015: [https://github.com/yellows8/oot3dhax].
| None
| App: Initial version. System: [[10.6.0-31]].
| March 11, 2015
| Around October 22, 2012
| [[User:Yellows8|Yellows8]]
|-
| Super Smash Bros 3DS
| Buffer overflow in local-multiplayer beacon handling.
| See [[smashbroshax|here]].
| App: v1.1.3
| See [[smashbroshax|here]]. System: [[10.3.0-28]].
| Time of exploit release.
| See [[smashbroshax|here]].
| [[User:Yellows8|Yellows8]]
|-
| Pokemon Super Mystery Dungeon
| Heap overflow within linear memory via unchecked save file length
| Pokemon Super Mystery Dungeon uses zlib compression for most of its save files, possibly due to the save files being larger than it's predecessor, Gates to Infinity. When a save file is being prepared to be loaded and read from, only a 0x32000 large buffer is allocated for file reading, and a 0x3e800-large buffer for decompression is also allocated before the file is read. However, the game does not limit the size of the file read to this allocation bound, allowing for the file to overflow into the linear memory heap and into the next allocation. Since Pokemon Super Mystery Dungeon stores allocation memchunks directly before the allocation, overwriting the next memchunk with a corrupted one allows for arbitrary writes of linear heap pointers when the next buffer is allocated or arbitrary writes of any pointer within writable memory when the corrupted buffer is freed.
| None
| [[10.7.0-32]].
| Time of exploit release.
| April 14, 2016
| [[User:Shinyquagsire23|Shiny Quagsire]]
|-
| VVVVVV
| Buffer overflow in XML save file array parsing
| VVVVVV utilizes several XML files (renamed with a .vvv extension) to store level save data, stats and settings. Within these XML files are several tags containing an array of data which, when parsed, is not properly checked to be of proper length for the tag being parsed from. This allows for an overflow of 16-bit array values from the location where the array is parsed. With unlock.vvv, XML data is parsed to the stack, and with level saves the heap. This allows for the pointer where the level save worldmap tag array should be parsed into to be overwritten with a stack address, allowing for ROP from within the XML array parsing function on the next level load.
| None
| [[10.7.0-32]].
| Time of exploit release.
| April 25, 2016
| [[User:Shinyquagsire23|Shiny Quagsire]]
|-
| Citizens of Earth
| Save file read stack smash
| Citizens of Earth also uses "XML" files for saves, which are actually entirely binary data (not XML at all) with no checksums. These files are read from the filesystem on to a fixed size stack buffer which leads to an incredibly trivial stack smash. When using the autosave slot for this, the save is parsed when the user selects "continue". When using one of the dedicated save slots (1-3), the save is parsed shortly after the company splash screens fade. Note that the save is read quite high (descending) on the stack - when exploiting this, one would likely need to move SP due to almost instantly overflowing the physical stack.
| None
| [[10.7.0-32]].
| Time of exploit release.
| May 5, 2016
| [[User:Dazzozo|Dazzozo]]
|}

==Useless crashes / applications which were fuzzed==
* Pushmo (3DSWare), QR codes: level name is properly limited to 16 characters, game doesn't crash with a longer name. The only possible crashes are triggered by out-of-bounds array index values, these crashes are not exploitable due to the index value being 8bit.

* [https://github.com/yellows8/mm3d_re The Legend of Zelda: Majora's Mask 3D]

* "The Legend of Zelda: A Link Between Worlds" and "The Legend of Zelda: Tri Force Heroes": these games don't crash at all when the entire save-file(minus constant header data) is overwritten with /dev/random output / 0xFF-bytes. All of the CRC32s were updated for this of course.

* Pokemon Mystery Dungeon: Gates to Infinity has the same unchecked file bounds as Pokemon Super Mystery Dungeon, however since save compression was introduced in Pokemon Super Mystery Dungeon, it only allocates one buffer within the application heap instead of several within the linear heap, resulting in nothing to corrupt or overwrite even if the file's length is extended past it's allocation.

* "Kid Icarus: Uprising": Overwriting the entire savedata results in various crashes, nothing useful.

* Savedata/extdata for "Super Smash Bros 3DS": Overwriting the various files stored under savedata/extdata results in useless crashes.

* "StarFox 64 3D": Doesn't crash at all with the entire savedata overwritten.

* "Frogger 3D": Overwriting a savefile with random-data results in *nothing* crashing.

* "Mutant Mudds": Overwriting the savefile with anything else than 0x00 results in the console rebooting

==Crashes needing investigation==
* Disney Infinity crashes when all savedata overwritten with /dev/urandom. No checksums. 0xFF bytes don't cause a crash.

* Football Up Online / Soccer Up Online and Football Up 3D / Soccer Up 3D crash when teamname(UTF-16) length = 0x48 AND 0x20 null bytes are removed after just the name or if teamname length is way longer than 0x48.

=System applications=
{| class="wikitable" border="1"
|-
! Summary
! Description
! Fixed in version
! Last version this flaw was checked for
! Timeframe this was discovered
! Discovered by
|-
| 3DS [[System Settings]] DS profile string stack-smash
| Too long or corrupted strings (01Ah 2 Nickname length in characters 050h 2 Message length in characters) in the NVRAM DS user settings (System Settings->Other Settings->Profile->Nintendo DS Profile) cause it to crash in 3DS-mode due to a stack-smash. The DSi is not vulnerable to this, DSi launcher(menu) and DSi System Settings will reset the NVRAM user-settings if the length field values are too long(same result as when the CRCs are invalid). TWL_FIRM also resets the NVRAM user-settings when the string-length(s) are too long.
| [[7.0.0-13]]
| [[7.0.0-13]]
| 2012
| [[User:Ichfly|Ichfly]]
|}

=System applets=
{| class="wikitable" border="1"
|-
! Summary
! Description
! Fixed in version
! Last version this flaw was checked for
! Introduced with version
! Timeframe info related to this was added to wiki
! Timeframe this was discovered
! Discovered by
|-
| [[Home Menu]] [[System_SaveData|NAND-savedata]] Launcher.dat icons
| The homemenu code processing the titleid list @ launcherdat+8 copies those titleIDs to another buffer, where the offset relative to that buffer is calculated using the corresponding s8/s16 entries. Those two values are not range checked at all. Hence, one can use this to write u64(s) with arbitrary values to before/after this allocated output buffer. See [[Home_Menu|here]] regarding Launcher.dat structure.

This can be exploited(with Launcher.dat loading at startup at least) by using a s16 for the icon entry with value 0xFFEC(-20)(and perhaps more icons with similar s16 values to write multiple u64s). The result is that the u64 value is written to outbuf-0xA0, which overwrites object+0(vtable) and object+4(doesn't matter here) for an object that gets used a bit after the vulnerable function triggers. The low 32bits of the u64 can then be set to the address of controlled memory(either outbuf in regular heap or the entire launcherdat buffer in linearmem), for use as a fake vtable in order to get control of PC. From there one can begin ROP via vtable funcptrs to do a stack-pivot(r4=objectaddr at the time the above object gets used).

Originally this vuln could only be triggered via Launcher.dat at Home Menu startup, right after Launcher.dat gets loaded + memory gets allocated, once the file-format version code is finished running. Starting with v9.6 this can be triggered when loading layouts from SD extdata as well. The vuln itself triggers before the layout data is written to Launcher.dat, but it doesn't seem to be possible to overwrite anything which actually gets used before the function which writes Launcher.dat into the layout gets called.

Home Menu has some sort of fail-safe system(or at least on v9.7) when Home Menu crashes due to Launcher.dat(this also applies for other things with Home Menu): after crashing once, Home Menu resets Launcher.dat to a state where it no longer crashes anymore. However, note that any exploits using this which hang/etc without crashing will still brick the system. '''Hence, attempting anything with this on physnand without hw-nand-access isn't really recommended.'''
| None
| [[10.3.0-28|10.3.0-X]]
|
|
| May 14, 2015
| [[User:Yellows8|Yellows8]]
|-
| [[Home Menu]] theme-data decompression buffer overflow ([[menuhax|themehax]])
| The only func-call size parameter used by the theme decompression function is one for the compressed size, none for the decompressed size. The decompressed-size value from the LZ header is used by this function to check when to stop decompressing, but this function itself has nothing to verify the decompressed_size with. The code calling this function does not check or even use the decompressed size from the header either.

This function is separate from the rest of the Home Menu code: the function used for decompressing themes is *only* used for decompressing themes, nothing else. There's a separate decompression function in Home Menu used for decompressing everything else.

That other decompression function in Home Menu handles decompression size properly(decompressed size check for max buffer size is done by code calling the other function, not in the function itself). Unlike the other function, the theme function supports multiple LZ algorithms, but the one which actually gets used in official themes is the same one supported by the other function anyway.

See also [[menuhax|here]].

With [[10.2.0-28|10.2.0-X]] Home Menu, the only code change was that the following was added right after theme-load and before actual decompression: "if(<get_lzheader_decompressed_size>(compressed_buf) > 0x150000)<exit>;". This fixed the vuln.
| [[10.2.0-28|10.2.0-X]]
| [[10.2.0-28|10.2.0-X]]
| <Old3DS/New3DS version which added initial theme support>
|
| December 22, 2014
| [[User:Yellows8|Yellows8]], [[User:Myria|Myria]] independently (~spring 2015)
|-
| [[Home Menu]] shuffle body-data buffer overflow ([[menuhax|shufflehax]])
| See [[menuhax|here]].
| [[10.6.0-31|10.6.0-X]]
| [[10.6.0-31|10.6.0-X]]
| [[9.3.0-21|9.3.0-X]]
|
| January 3, 2015
| [[User:Yellows8|Yellows8]]
|-
| [[Home Menu]] extdata SaveData.dat loading buffer overflow
| ''This was not tested on hardware.''

The extdata SaveData.dat file-reading code allocates a fixed-size heap buffer for the expected SaveData.dat filesize, then reads the filedata into this buffer using the actual FS filesize. Before v5.0 the filesize used here wasn't validated, hence if the filesize is larger than alloc_size a buffer overflow would occur. ''After'' doing the file-read it does validate that the actual_readsize matches the alloc_size, but at this point the buffer overflow has already occurred.

It's unknown whether v5.0 had similar changes for other extdata file-loading code.
| [[5.0.0-11|5.0.0-X]]
|
| [[2.0.0-2|2.0.0-X]]
| June 9, 2016
| June 9, 2016
| [[User:Yellows8|Yellows8]]
|-
| Webkit/web-browser bugs
| spider has had at least three different code-execution exploits. Majority of them are use-after-free issues. See also [[browserhax|here]].
|
|
|
| 2013?
|
| A lot of people.
|-
| Old3DS/New3DS [[Internet_Browser|Browser-version-check]] bypass
| When the browser-version-check code runs where the savedata for it was never initialized(such as when the user used the "Initialize savedata" option), it will use base_timestamp=0 instead of the timestamp loaded from savedata. This is then used with "if(cur_timestamp - base_timestamp >= <24h timestamp>){Run browser-version-check HTTPS request code}".
Hence, if the savedata was just initialized, and if the system datetime is set to before January 2, 2000, the browser-version-check will be skipped. This includes January 1, 2000, 00:00, because that's the epoch(timestamp value 0x0) used with this timestamp.

See [http://yls8.mtheall.com/3dsbrowserhax.php here] for bypass usage instructions.

This was fixed with [[10.7.0-32|10.7.0-32]], see [[Internet_Browser|here]] for details.
| [[10.7.0-32|10.7.0-32]]
|
| [[9.9.0-26|9.9.0-26]]
| February 25, 2016
| November 2, 2015 (Exactly one week after the browser version pages were initially updated server-side)
| [[User:Yellows8|Yellows8]]
|}

==Useless crashes==
Old3DS system web-browser:
* 2^32 characters long string(''finally'' fixed with v10.6): this is similar to the vulnerability fixed [http://git.chromium.org/gitweb/?p=external/Webkit.git;a=commitdiff;h=ec471f16fbd1f879cb631f9b022fd16acd75f4d4 here], concat-large-strings-crash2.html triggers a crash which is about the same as the one triggered by a 2^32 string. Most of the time this vulnerability will cause a memory page permissions fault, since the WebKit code attempts to copy the string text data to the output buffer located in read-only [[CRO0|CRO]] heap memory. The only difference between a crash triggered by a 2^32 string and the concat-large-strings-crash2.html crash is at the former copies the string data using the original string length(like 1 text character for "x", 4 for "xxxx") while the latter attempts to copy >12MB. In some ''very'' rare cases a thread separate from the string data-copy thread will crash, this might be exploitable. However, this is mostly useless since it rarely crashes this way.

* Trying to directly load a page via the browser "URL" option with [https://github.com/yellows8/3ds_browserhax_common webkitdebug] setup, causes a crash to trigger in oss.cro due to an use-after-free being caught with webkitdebug. This is presumably some sort of realloc() issue in the libcurl version used by the <={v10.2-v10.3} browser. This happens with *every* *single* *page* one tries to load via the "URL" option, but not when loading links on the current page, hence this is probably useless. A different use-after-free with realloc triggers with loading any page at all regardless of method too(libcurl probably).

* This WebKit build has ''a lot'' of crash-trigger bugs that only happen with [https://github.com/yellows8/3ds_browserhax_common webkitdebug] completely setup(addr accesses near 0x0), with ''just'' trying to load any page at all.

3DS Userland Flaws

2016-06-16T13:24:01Z

LiquidFenrir: /* Useless crashes / applications which were fuzzed */

This page lists vulnerabilities / exploits for 3DS applications and applets. Exploiting these initially results in ROP, from that ROP one can then for example try exploiting [[3DS_System_Flaws|system]] flaw(s).

=Non-system applications=
{| class="wikitable" border="1"
|-
! Application name
! Summary
! Description
! Fixed in app/system version
! Last app/system version this flaw was checked for
! Timeframe info related to this was added to wiki
! Timeframe this vuln was discovered
! Vuln discovered by
|-
| Cubic Ninja
| Map-data stack smash
| See [[Ninjhax|here]] regarding Ninjhax.
| None
| App: Initial version. System: [[10.4.0-29]].
| Ninjhax release
| July 2014
| [[User:smea|smea]]
|-
| The Legend of Zelda: Ocarina of Time 3D
| UTF-16 name string buffer overflow via unchecked u8 length field
| The u8 at offset 0x2C in the savefile is the character-length of the UTF-16 string at offset 0x1C. When copying this string, it's essentially a memory-copy with lenval*2, not a string-copy. This can be used to trigger buffer overflows at various locations depending on the string length.
* When value is >=0x6E it crashes when saving the saveslot, this causes a stack-smash however it normally crashes before it returns from the function which had the stack-frame overwritten.
* With value >=0x9A, it crashes via stack-smash in-game once any dialogs are opened(touching buttons on the touch-screen can trigger it too).
* Length value>=0xCD causes a crash while loading the saveslot, via a heap buffer overflow. This buf-overflow overwrites a heap memchunk following the allocated buffer. When the first 16-bits overwriting that heap memchunk is not the memchunk magic-number(0x7373), the mem-alloc code will just return a NULL ptr which later results in a crash. When the magic-number is valid, the mem-alloc code will continue to attempt to parse the memchunk, which may crash depending on the data which overwrote the memchunk. This heap code is separate from the CTRSDK heap code. Exploiting this doesn't seem to be possible: since the heap code actually verifies that the magic-number for the next/prev memchunk ptrs are correct(unlike CTRSDK), it's not possible to change those ptrs to useful arbitrary addresses outside of savedata(like with triggering a write to a c++ object ptr which later is used with a vtable func-call, this is what one would do with CTRSDK heap here).

On March 11, 2015, an exploit using this vuln was released, that one was intended for warez/etc. The following exploit wasn't released before then mainly because doing so would (presumably) result in the vuln being fixed. The following old exploit was released on March 14, 2015: [https://github.com/yellows8/oot3dhax].
| None
| App: Initial version. System: [[10.6.0-31]].
| March 11, 2015
| Around October 22, 2012
| [[User:Yellows8|Yellows8]]
|-
| Super Smash Bros 3DS
| Buffer overflow in local-multiplayer beacon handling.
| See [[smashbroshax|here]].
| App: v1.1.3
| See [[smashbroshax|here]]. System: [[10.3.0-28]].
| Time of exploit release.
| See [[smashbroshax|here]].
| [[User:Yellows8|Yellows8]]
|-
| Pokemon Super Mystery Dungeon
| Heap overflow within linear memory via unchecked save file length
| Pokemon Super Mystery Dungeon uses zlib compression for most of its save files, possibly due to the save files being larger than it's predecessor, Gates to Infinity. When a save file is being prepared to be loaded and read from, only a 0x32000 large buffer is allocated for file reading, and a 0x3e800-large buffer for decompression is also allocated before the file is read. However, the game does not limit the size of the file read to this allocation bound, allowing for the file to overflow into the linear memory heap and into the next allocation. Since Pokemon Super Mystery Dungeon stores allocation memchunks directly before the allocation, overwriting the next memchunk with a corrupted one allows for arbitrary writes of linear heap pointers when the next buffer is allocated or arbitrary writes of any pointer within writable memory when the corrupted buffer is freed.
| None
| [[10.7.0-32]].
| Time of exploit release.
| April 14, 2016
| [[User:Shinyquagsire23|Shiny Quagsire]]
|-
| VVVVVV
| Buffer overflow in XML save file array parsing
| VVVVVV utilizes several XML files (renamed with a .vvv extension) to store level save data, stats and settings. Within these XML files are several tags containing an array of data which, when parsed, is not properly checked to be of proper length for the tag being parsed from. This allows for an overflow of 16-bit array values from the location where the array is parsed. With unlock.vvv, XML data is parsed to the stack, and with level saves the heap. This allows for the pointer where the level save worldmap tag array should be parsed into to be overwritten with a stack address, allowing for ROP from within the XML array parsing function on the next level load.
| None
| [[10.7.0-32]].
| Time of exploit release.
| April 25, 2016
| [[User:Shinyquagsire23|Shiny Quagsire]]
|-
| Citizens of Earth
| Save file read stack smash
| Citizens of Earth also uses "XML" files for saves, which are actually entirely binary data (not XML at all) with no checksums. These files are read from the filesystem on to a fixed size stack buffer which leads to an incredibly trivial stack smash. When using the autosave slot for this, the save is parsed when the user selects "continue". When using one of the dedicated save slots (1-3), the save is parsed shortly after the company splash screens fade. Note that the save is read quite high (descending) on the stack - when exploiting this, one would likely need to move SP due to almost instantly overflowing the physical stack.
| None
| [[10.7.0-32]].
| Time of exploit release.
| May 5, 2016
| [[User:Dazzozo|Dazzozo]]
|}

==Useless crashes / applications which were fuzzed==
* Pushmo (3DSWare), QR codes: level name is properly limited to 16 characters, game doesn't crash with a longer name. The only possible crashes are triggered by out-of-bounds array index values, these crashes are not exploitable due to the index value being 8bit.

* [https://github.com/yellows8/mm3d_re The Legend of Zelda: Majora's Mask 3D]

* "The Legend of Zelda: A Link Between Worlds" and "The Legend of Zelda: Tri Force Heroes": these games don't crash at all when the entire save-file(minus constant header data) is overwritten with /dev/random output / 0xFF-bytes. All of the CRC32s were updated for this of course.

* Pokemon Mystery Dungeon: Gates to Infinity has the same unchecked file bounds as Pokemon Super Mystery Dungeon, however since save compression was introduced in Pokemon Super Mystery Dungeon, it only allocates one buffer within the application heap instead of several within the linear heap, resulting in nothing to corrupt or overwrite even if the file's length is extended past it's allocation.

* "Kid Icarus: Uprising": Overwriting the entire savedata results in various crashes, nothing useful.

* Savedata/extdata for "Super Smash Bros 3DS": Overwriting the various files stored under savedata/extdata results in useless crashes.

* "StarFox 64 3D": Doesn't crash at all with the entire savedata overwritten.

* "Frogger 3D": Overwriting a savefile with random-data results in *nothing* crashing.

* "Mutant Mudds": Overwriting the savefile with random-data or filling it with anything else than 0x00 results in the console rebooting

==Crashes needing investigation==
* Disney Infinity crashes when all savedata overwritten with /dev/urandom. No checksums. 0xFF bytes don't cause a crash.

* Football Up Online / Soccer Up Online and Football Up 3D / Soccer Up 3D crash when teamname(UTF-16) length = 0x48 AND 0x20 null bytes are removed after just the name or if teamname length is way longer than 0x48.

=System applications=
{| class="wikitable" border="1"
|-
! Summary
! Description
! Fixed in version
! Last version this flaw was checked for
! Timeframe this was discovered
! Discovered by
|-
| 3DS [[System Settings]] DS profile string stack-smash
| Too long or corrupted strings (01Ah 2 Nickname length in characters 050h 2 Message length in characters) in the NVRAM DS user settings (System Settings->Other Settings->Profile->Nintendo DS Profile) cause it to crash in 3DS-mode due to a stack-smash. The DSi is not vulnerable to this, DSi launcher(menu) and DSi System Settings will reset the NVRAM user-settings if the length field values are too long(same result as when the CRCs are invalid). TWL_FIRM also resets the NVRAM user-settings when the string-length(s) are too long.
| [[7.0.0-13]]
| [[7.0.0-13]]
| 2012
| [[User:Ichfly|Ichfly]]
|}

=System applets=
{| class="wikitable" border="1"
|-
! Summary
! Description
! Fixed in version
! Last version this flaw was checked for
! Introduced with version
! Timeframe info related to this was added to wiki
! Timeframe this was discovered
! Discovered by
|-
| [[Home Menu]] [[System_SaveData|NAND-savedata]] Launcher.dat icons
| The homemenu code processing the titleid list @ launcherdat+8 copies those titleIDs to another buffer, where the offset relative to that buffer is calculated using the corresponding s8/s16 entries. Those two values are not range checked at all. Hence, one can use this to write u64(s) with arbitrary values to before/after this allocated output buffer. See [[Home_Menu|here]] regarding Launcher.dat structure.

This can be exploited(with Launcher.dat loading at startup at least) by using a s16 for the icon entry with value 0xFFEC(-20)(and perhaps more icons with similar s16 values to write multiple u64s). The result is that the u64 value is written to outbuf-0xA0, which overwrites object+0(vtable) and object+4(doesn't matter here) for an object that gets used a bit after the vulnerable function triggers. The low 32bits of the u64 can then be set to the address of controlled memory(either outbuf in regular heap or the entire launcherdat buffer in linearmem), for use as a fake vtable in order to get control of PC. From there one can begin ROP via vtable funcptrs to do a stack-pivot(r4=objectaddr at the time the above object gets used).

Originally this vuln could only be triggered via Launcher.dat at Home Menu startup, right after Launcher.dat gets loaded + memory gets allocated, once the file-format version code is finished running. Starting with v9.6 this can be triggered when loading layouts from SD extdata as well. The vuln itself triggers before the layout data is written to Launcher.dat, but it doesn't seem to be possible to overwrite anything which actually gets used before the function which writes Launcher.dat into the layout gets called.

Home Menu has some sort of fail-safe system(or at least on v9.7) when Home Menu crashes due to Launcher.dat(this also applies for other things with Home Menu): after crashing once, Home Menu resets Launcher.dat to a state where it no longer crashes anymore. However, note that any exploits using this which hang/etc without crashing will still brick the system. '''Hence, attempting anything with this on physnand without hw-nand-access isn't really recommended.'''
| None
| [[10.3.0-28|10.3.0-X]]
|
|
| May 14, 2015
| [[User:Yellows8|Yellows8]]
|-
| [[Home Menu]] theme-data decompression buffer overflow ([[menuhax|themehax]])
| The only func-call size parameter used by the theme decompression function is one for the compressed size, none for the decompressed size. The decompressed-size value from the LZ header is used by this function to check when to stop decompressing, but this function itself has nothing to verify the decompressed_size with. The code calling this function does not check or even use the decompressed size from the header either.

This function is separate from the rest of the Home Menu code: the function used for decompressing themes is *only* used for decompressing themes, nothing else. There's a separate decompression function in Home Menu used for decompressing everything else.

That other decompression function in Home Menu handles decompression size properly(decompressed size check for max buffer size is done by code calling the other function, not in the function itself). Unlike the other function, the theme function supports multiple LZ algorithms, but the one which actually gets used in official themes is the same one supported by the other function anyway.

See also [[menuhax|here]].

With [[10.2.0-28|10.2.0-X]] Home Menu, the only code change was that the following was added right after theme-load and before actual decompression: "if(<get_lzheader_decompressed_size>(compressed_buf) > 0x150000)<exit>;". This fixed the vuln.
| [[10.2.0-28|10.2.0-X]]
| [[10.2.0-28|10.2.0-X]]
| <Old3DS/New3DS version which added initial theme support>
|
| December 22, 2014
| [[User:Yellows8|Yellows8]], [[User:Myria|Myria]] independently (~spring 2015)
|-
| [[Home Menu]] shuffle body-data buffer overflow ([[menuhax|shufflehax]])
| See [[menuhax|here]].
| [[10.6.0-31|10.6.0-X]]
| [[10.6.0-31|10.6.0-X]]
| [[9.3.0-21|9.3.0-X]]
|
| January 3, 2015
| [[User:Yellows8|Yellows8]]
|-
| [[Home Menu]] extdata SaveData.dat loading buffer overflow
| ''This was not tested on hardware.''

The extdata SaveData.dat file-reading code allocates a fixed-size heap buffer for the expected SaveData.dat filesize, then reads the filedata into this buffer using the actual FS filesize. Before v5.0 the filesize used here wasn't validated, hence if the filesize is larger than alloc_size a buffer overflow would occur. ''After'' doing the file-read it does validate that the actual_readsize matches the alloc_size, but at this point the buffer overflow has already occurred.

It's unknown whether v5.0 had similar changes for other extdata file-loading code.
| [[5.0.0-11|5.0.0-X]]
|
| [[2.0.0-2|2.0.0-X]]
| June 9, 2016
| June 9, 2016
| [[User:Yellows8|Yellows8]]
|-
| Webkit/web-browser bugs
| spider has had at least three different code-execution exploits. Majority of them are use-after-free issues. See also [[browserhax|here]].
|
|
|
| 2013?
|
| A lot of people.
|-
| Old3DS/New3DS [[Internet_Browser|Browser-version-check]] bypass
| When the browser-version-check code runs where the savedata for it was never initialized(such as when the user used the "Initialize savedata" option), it will use base_timestamp=0 instead of the timestamp loaded from savedata. This is then used with "if(cur_timestamp - base_timestamp >= <24h timestamp>){Run browser-version-check HTTPS request code}".
Hence, if the savedata was just initialized, and if the system datetime is set to before January 2, 2000, the browser-version-check will be skipped. This includes January 1, 2000, 00:00, because that's the epoch(timestamp value 0x0) used with this timestamp.

See [http://yls8.mtheall.com/3dsbrowserhax.php here] for bypass usage instructions.

This was fixed with [[10.7.0-32|10.7.0-32]], see [[Internet_Browser|here]] for details.
| [[10.7.0-32|10.7.0-32]]
|
| [[9.9.0-26|9.9.0-26]]
| February 25, 2016
| November 2, 2015 (Exactly one week after the browser version pages were initially updated server-side)
| [[User:Yellows8|Yellows8]]
|}

==Useless crashes==
Old3DS system web-browser:
* 2^32 characters long string(''finally'' fixed with v10.6): this is similar to the vulnerability fixed [http://git.chromium.org/gitweb/?p=external/Webkit.git;a=commitdiff;h=ec471f16fbd1f879cb631f9b022fd16acd75f4d4 here], concat-large-strings-crash2.html triggers a crash which is about the same as the one triggered by a 2^32 string. Most of the time this vulnerability will cause a memory page permissions fault, since the WebKit code attempts to copy the string text data to the output buffer located in read-only [[CRO0|CRO]] heap memory. The only difference between a crash triggered by a 2^32 string and the concat-large-strings-crash2.html crash is at the former copies the string data using the original string length(like 1 text character for "x", 4 for "xxxx") while the latter attempts to copy >12MB. In some ''very'' rare cases a thread separate from the string data-copy thread will crash, this might be exploitable. However, this is mostly useless since it rarely crashes this way.

* Trying to directly load a page via the browser "URL" option with [https://github.com/yellows8/3ds_browserhax_common webkitdebug] setup, causes a crash to trigger in oss.cro due to an use-after-free being caught with webkitdebug. This is presumably some sort of realloc() issue in the libcurl version used by the <={v10.2-v10.3} browser. This happens with *every* *single* *page* one tries to load via the "URL" option, but not when loading links on the current page, hence this is probably useless. A different use-after-free with realloc triggers with loading any page at all regardless of method too(libcurl probably).

* This WebKit build has ''a lot'' of crash-trigger bugs that only happen with [https://github.com/yellows8/3ds_browserhax_common webkitdebug] completely setup(addr accesses near 0x0), with ''just'' trying to load any page at all.