Vulnerabilities: Difference between revisions

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== System ==
== System ==
== libtiff exploit #1 (TIFF Exploit 2.00) <=2.00 ===
Discovered on 2005-09-23.
Implemented in downgraders (like MPH downgrader to 1.50) and eLoader by Fanjita.
https://en.wikibooks.org/wiki/PSP/Homebrew_History#The_TIFF_Exploit
== libtiff exploit #2 (TIFF Exploit 2.71) <=2.71 ===
Discovered in 2006-09.
Implemented in Kriek eLoader and xLoader by Team N00bz.
https://en.wikibooks.org/wiki/PSP/Homebrew_History#The_TIFF_Exploit
=== libtiff exploit #3 (TIFF Exploit 4.20) by wololo <=4.20 ===
Discovered in 2008-08. Released on 2009-03-15.
https://wololo.net/2009/03/15/so-what-about-the-libtiff-vulnerability/
https://www.youtube.com/watch?v=RUJnXADjxsw
https://web.archive.org/web/20111226013924/http://secunia.com/advisories/31610/
=== libtiff exploit #4 (eggsploit) by Malloxis, Matiaz and davee <=5.05 ===
Discovered in 2009-03-15 by Malloxis. Released on 2009-04-12 by Matiaz and davee.
https://www.dcemu.co.uk/vbulletin/threads/197302-5-03-TIFF-Hello-World
https://wololo.net/2009/04/13/eggsplanations/
https://www.youtube.com/watch?v=wV21QqQmX_o


=== Old System PRX allowed ===
=== Old System PRX allowed ===

Revision as of 14:43, 7 October 2023

Usermode

Game savedata

Acid_snake exploits to sort

https://bitbucket.org/Acid_Snake/ark-2/src/master/exploit/usploit/

Before PS Vita era

Grand Theft Auto: Liberty City Stories UMD: <=?3.03?

Lumines ?<=3.50?

Gripshift by Matiaz: <=5.02?-5.03?. Patched 5.05

Patapon 2 demo (USA) by Malloxis: ?PSP <=6.20?

Medal Of Honor Heroes, or Heroes 2, or both by kgsws: ?

During PS Vita era

Everybody's Tennis: <= 1.61

Motorstorm: Arctic Edge: <= 1.61. Patched 1.65

Super Collapse 3 (ULES01027, ULUS10287, NPHH00031) by Bryan Keller: <= 1.67. Patched 1.69?0?, 2014-11-10

https://github.com/bryankeller/PSP-Exploit-Super-Collapse-3

https://code.google.com/archive/p/valentine-hbl/source/default/source

Monster Hunter Freedom Unite, Monster Hunter Freedom 2, Monster Hunter Portable 2ndG, Monster Hunter Portable 3rd: <= 1.80. Patched 1.81

Mad Blocker Alpha: <= 1.81. Patched on 2.00

Gravity Crash Portable by teck4 and frostegater: <= ?1.81?

Urbanix first exploit: <= 1.81. Patched 2.00

UNO by xiaolin, zer01ne, MaxiExtreme and frostegater: <= 2.02. Patched 2.05

Apache Overkill by Tomtomdu80: <= 2.06

Gamocracy One: Legend of Robot (Europe), Gamocracy One: Legend of Robot (USA) by qwikrazor87: <= 2.12

https://code.google.com/archive/p/valentine-hbl/source/default/source

Arcade Air Hockey & Bowling (Europe), Arcade Air Hockey & Bowling (USA), Arcade Pool & Snooker (Europe), Arcade Pool & Snooker (USA), World of Pool, Arcade Darts (Europe), Arcade Darts (USA) by Acid_snake: <=2.60. Patched 2.61

https://code.google.com/archive/p/valentine-hbl/source/default/source

"Jikkyou Powerful Pro Yakyu 2012 Ketteiban" (Japanese: 実況パワフルプロ野球 2012決定版): <= 2.61

Pipe Madness: <= 2.61. Patched 3.00

Jewel Keepers: <= 2.61. Patched 3.00

Half Minute Hero: <= 2.61. Patched 3.00

FieldRunners by frostegater: <= 2.61. Patched 3.00

Urbanix second exploit: <= 2.61. Patched 3.00

Cubixx: <= 3.00. Patched 3.01

Ben 10 Alien Force: Vilgax Attacks: <= 3.01. Patched 3.10

King Of Pool by qwikrazor87: <= 3.01. Patched 3.10

101-in-1 Megamix by xerpi: <= 3.01. Patched 3.10

Fifa 2011, Fifa 2012: <= 3.01. Patched 3.10

Persona 2: Innocent Sin, Persona 2: Tsumi: <= 3.01. Patched 3.10

Arcade Airhockey & Bowling, Arcade Pool & Snooker, World of Pool, Pool Hall Pro: <= 3.01. Patched 3.10

"Jikkyou Powerful Pro Yakyu 2012 Ketteiban" (Japanese: 実況パワフルプロ野球 2012決定版): <= 3.12

MyStylist: <= 3.15

Skate Park City: <= 3.15. Patched 3.18

Space Invaders Extreme: <= 3.18

Z.H.P.: Unlosing Ranger VS Darkdeath Evilman (NPEH00099, ULUS10559, ULJS00262) by KanadeEngel and qwikrazor87: <= 3.18

https://github.com/KanadeEngel/PSP/tree/master/Exploits/Usermode/Zettei%20Hero%20Project%20-%203.18%20Exploit

https://code.google.com/archive/p/valentine-hbl/source/default/source

Gladiator Begins: <= 3.18

Patapon 1: <= 3.18

Talkman Travel: Tokyo: <= 3.18

Go! Sudoku (UCES00152): <= 3.30

https://code.google.com/archive/p/valentine-hbl/source/default/source

Arcade Darts: <= 3.36

Patapon 2 non-demo (UCES01177): <=3.36

https://wololo.net/2019/08/13/hacking-consoles-a-learning-journey-part-4/

https://github.com/TheOct0/patapon_exploit

https://github.com/wololo-learning-journey/patapon_exploit

https://code.google.com/archive/p/valentine-hbl/source/default/source

Numblast: <= 3.36

Hot Brain: <= 3.36

Hatsune Miku: Project DIVA extend: <= 3.36

https://code.google.com/archive/p/valentine-hbl/source/default/source

Ape Escape: On the Loose: <= 3.50. Patched 3.51

"Toukiden: Kiwami (DEMO)" (討鬼伝 極 体験版) by 173210: <= 3.51

https://code.google.com/archive/p/valentine-hbl/source/default/source

Puzzle Scape: <= 3.52

World of Pool, Pool Hall Pro: <= 3.52

Metal Gear Solid Portable OPS+ by 173210: <= 3.57

https://github.com/173210/psp_exploits/

After PS Vita era

ScrabbleTM by ChampionLeake: probably not patched, 2018-05-17

https://github.com/ChampionLeake/scrabblehax

Carol Vorderman's Sudoku by ChampionLeake: probably not patched, 2019-04-22

https://github.com/ChampionLeake/SudokuSTACK

Remarks

PSP demo are usually not exploitable because do not use the savedata feature. Patapon 2 has been an exception to this up to PS Vita System Software version 3.18/3.20, at least.

https://wololo.net/2014/04/18/pspvita-how-to-find-your-own-exploits/

http://wololo.net/2009/03/11/finding-gamesaves-exploits-on-the-psp/

https://wololo.net/2009/10/10/looking-for-vulnerabilities-in-the-psp-firmware/

System

libtiff exploit #1 (TIFF Exploit 2.00) <=2.00 =

Discovered on 2005-09-23.

Implemented in downgraders (like MPH downgrader to 1.50) and eLoader by Fanjita.

https://en.wikibooks.org/wiki/PSP/Homebrew_History#The_TIFF_Exploit

libtiff exploit #2 (TIFF Exploit 2.71) <=2.71 =

Discovered in 2006-09.

Implemented in Kriek eLoader and xLoader by Team N00bz.

https://en.wikibooks.org/wiki/PSP/Homebrew_History#The_TIFF_Exploit

libtiff exploit #3 (TIFF Exploit 4.20) by wololo <=4.20

Discovered in 2008-08. Released on 2009-03-15.

https://wololo.net/2009/03/15/so-what-about-the-libtiff-vulnerability/

https://www.youtube.com/watch?v=RUJnXADjxsw

https://web.archive.org/web/20111226013924/http://secunia.com/advisories/31610/

libtiff exploit #4 (eggsploit) by Malloxis, Matiaz and davee <=5.05

Discovered in 2009-03-15 by Malloxis. Released on 2009-04-12 by Matiaz and davee.

https://www.dcemu.co.uk/vbulletin/threads/197302-5-03-TIFF-Hello-World

https://wololo.net/2009/04/13/eggsplanations/

https://www.youtube.com/watch?v=wV21QqQmX_o

Old System PRX allowed

Discovered around 2005.

It is possible to overwrite the PSP flash memory with older System Software files. The version of these files is not checked.

Back to the SE/OE firmwares days, there was a 1.50 / 2.71 hybrid firmware.

Infinity 1 uses a built in 6.31 FW and reloads into 6.60/6.61 FW with patches. The catalyst for this hybrid firmware is the giraffe bug applied to systimer.prx. I chose this specific module only due to its size. Weighing in at only 3 KB compressed and 7 KB uncompressed it is the smallest PRX before init.prx. Size is important here – the PSP NAND is nearly at capacity under normal circumstances so we have to make savings. In fact, on the original phat PSP the NAND cannot contain both 6.61 and the 6.31 subset firmware. The infinity installer actually excludes some features (location free TV) so everything important can be installed.

Infinity 2 uses a signed usermode system PRX.

https://github.com/DaveeFTW/Infinity

https://infinity.lolhax.org/

https://lolhax.org/2017/09/24/6-61-infinity-an-explanation/

The same vulnerability is present at least partially in PS3 even on latest System Software version. It allows to downgrade the WebKit version to exploit it.

Fixed: no.

Unsigned System PRX allowed

Discovered in 2011 by kgsws.

When the PS3 was hacked and a selection of PSP encryption keys were released, this allowed one to sign his own usermode applications. HEN/CFW can be loaded much faster through a signed application rather than loading of a game. We can now sign our own vshmain and replace a step in the bootchain.

kgsws first demonstrated this bootchain injection back in 2011 and lead to the creation of 6.20 permanent custom firmware. Sony did patch this up in later firmware by applying an ECDSA signature to PRX files in the bootchain which we cannot forge.

Fixed: since PSP System Software version 6.30.

Kernel

kernel execution using encrypted UID planting Type Confusion kexploit by qwikrazor87 (Trinity, ARK-4): PS Vita 3.60-3.74

https://theofficialflow.github.io/2019/06/18/trinity.html#type-confusion https://github.com/TheOfficialFloW/Trinity/blob/master/eboot/mips.c https://github.com/PSP-Archive/ARK-4/blob/main/loader/live/kernel/kxploit/vita360/kxploit.c It involves AES enc/dec (using sceChnnlsv buffer in kernel RAM for fake thread UID) for it to work with the sceKernelDeleteThread UID kexploit.

kernel arbitrary read using sceNpCore_8AFAB4A0 double-fetch race condition kexploit by qwikrazor87 (Trinity, ARK-4): PS Vita 3.70

https://theofficialflow.github.io/2019/06/18/trinity.html#double-fetch-race-condition https://github.com/TheOfficialFloW/Trinity/blob/master/eboot/mips.c https://github.com/PSP-Archive/ARK-4/blob/main/loader/live/kernel/kxploit/vita360/kxploit.c

VPL kexploit: PS Vita 3.00-3.52

https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceVpl/kxploit.c https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/vpl/kxploit.c

sceKernelDeleteThread UID kexploit by qwikrazor87: PS Vita <=3.50

https://github.com/GuidoAlessandroMenichetti/kxploits

sceVideocodec kexploit: PS Vita 3.30-3.36

https://github.com/GuidoAlessandroMenichetti/kxploits https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceVideocodec/kxploit.c

_sceSdGetLastIndex kexploit (TN-X, TN-V) by qwikrazor87: PS Vita 3.18-3.20

https://github.com/173210/TN-Rev/blob/master/loader/main.c https://github.com/GuidoAlessandroMenichetti/kxploits https://bitbucket.org/Acid_Snake/ark-2/src/master/exploit/kxploit/sceSdGetLastIndex/kxploit.c https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceSdGetLastIndex/kxploit.c https://github.com/PSP-Archive/ARK-4/blob/main/loader/live/kernel/kxploit/vita320/kxploit.c

_sceLoadCertFromFlash kexploit (TN-V): PS Vita <3.18

https://github.com/GuidoAlessandroMenichetti/TN-Rev/blob/master/loader/main.c https://bitbucket.org/Acid_Snake/ark-2/src/master/exploit/kxploit/loadCertFromFlash/kxploit.c https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceLoadCertFromFlash/kxploit.c

sceWlanGetEtherAddr kexploit: PS Vita 1.61-1.80

https://bitbucket.org/Acid_Snake/ark-2/src/master/exploit/kxploit/wlanGetEtherAddr/kxploit.c https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceWlanGetEtherAddr/kxploit.c

_sceG729EncodeTermResource kexploit: PS Vita FW unk

https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceG729/kxploit.c

sceWlanDrv kexploit: PS Vita FW unk

https://bitbucket.org/Acid_Snake/ark-2/src/master/exploit/kxploit/wlanDrvLib/kxploit.c https://bitbucket.org/Acid_Snake/ark-4/src/master/kxploit/sceWlanDrvLib/kxploit.c

sceNetMCopyback kernel arbitrary read by qwikrazor87 and AcidSnake (ARK-4): PSP <=6.61

https://github.com/PSP-Archive/ARK-4/blob/main/loader/live/kernel/rodumper/main.c PSP implementation of sceNetMCopyback does not check the pointers passed in. As there is no DACR in PSP nor PSPemu, kernel pointers can be passed. As it does a signed 32-bit comparison, returning different values for a0 <= a1 and a0 > a1, this function can be used to bruteforce the value at a kernel address. TBD:implementation by CelesteBlue This vulnerability lets you compare the value at any place in kernel memory with whatever value you pass to it. There are 32 bits of data so you iterate 32 times. On each iteration, you determine the value of the current bit (0 or 1) by doing one comparison.

sceRtcCompareTick kernel arbitrary read by davee: PSP <=6.61

PSP implementation of sceRtcCompareTick does not check the pointers passed in. As there is no DACR in PSP nor PSPemu, kernel pointers can be passed. As it does a 64-bit comparison, returning different values for a0 < a1, a0 == a1, and a0 > a1, this function can be used to bruteforce the value at a kernel address. This vulnerability was used by Davee to make the first PSPemu kernel dump. TBD:implementation by CelesteBlue This vulnerability lets you compare the value at any place in kernel memory with whatever value you pass to it. There are 64 bits of data so you iterate 64 times. On each iteration, you determine the value of the current bit (0 or 1) by doing one comparison.

sceNetMPulldown (also called ifhandle 6.60-6.61) kexploit by davee (PROCFW, Chronoswitch, Infinity 2): PSP 6.60-6.61

https://github.com/uofw/uofwinst/blob/master/PXE/Launcher/kxp_660.c https://github.com/DaveeFTW/Infinity/blob/master/kexploit/src/k660.cpp https://github.com/DaveeFTW/Chronoswitch/blob/master/src/kernel_exploit.c https://github.com/PSP-Archive/ARK-4/blob/main/loader/live/kernel/kxploit/psp660/kxploit.c

sceHttpStorageOpen kexploit, 0xFFFFFFFFailSploit, write 0xFFFFFFFF to anywhere by some1, liquidzigong, SmikY (Chronoswitch): PSP 6.20-6.61

https://wololo.net/talk/viewtopic.php?t=6612 https://github.com/DaveeFTW/Chronoswitch/blob/master/src/kernel_exploit.c https://github.com/smiky/psptools/blob/master/kxploit/main.c

sceUtilityPowerRegisterCallback kexploit by TN and davee with sceKernelUtilsMd5BlockInit kexploit to keep the data dynamic (TN-HEN, Chronoswitch): PSP 6.20-6.35

https://lolhax.org/2010/12/23/arcanum/ https://wololo.net/talk/viewtopic.php?f=5&t=947 https://github.com/DaveeFTW/Chronoswitch/blob/master/src/kernel_exploit.c

ifhandle 5.70 race condition kexploit by davee: PSP 5.00-5.70, patched on PSP 6.20

https://wololo.net/talk/viewtopic.php?f=5&t=11877&start=10

sceDRMInstallGetFileInfo memset anywhere (also called psheet 5.03) kexploit by davee, lack of k1 checks (ChickHEN): PSP <=5.03

https://wololo.net/talk/viewtopic.php?p=2022 https://wololo.net/talk/viewtopic.php?f=5&t=242 http://www.kingx.de/forum/showthread.php?tid=15275 The psheet exploit clobbers 16 bytes of kernel memory, so it is needed to read kernel memory before exploiting and restore the other 12 after.

registry error store: PSP <=2.80

sceKernelLoadExec buffer overflow by hitchhikr / Neural: PSP 2.01-2.60

https://forums.ps2dev.org/viewtopic.php?t=6091 https://www.hitchhikr.net/Exploit_2.6.zip

reused index.dat key: PSP 2.00, 2.01

swaptrick/kxploit: PSP <=1.50

kernel flagged ELF: PSP <=1.00

Remarks

https://www.pspx.ru/forum/showthread.php?t=97295

IPL

Giraffe bug

Discovered in 2016 by davee.

There is a bug in PRX loading. It turns out loadcore is a bit indecisive about what it does with the optional and rarely used ~SCE header. This header is 64 bytes long and mostly unused other than a 32 bit size/offset field (lets call it sce_size) at +4 in the header. The main PRX decryption function sceKernelCheckExecFile just skips past the 64 bytes when it detects that sce_size is positive. sceKernelLoadExecutableObject, the actual ELF loading aspect of loadcore does the same thing. However, sceKernelProbeExecutableObject, which is used to get information about the PRX meta-data, skips past sce_size bytes. This inconsistency leads to the loading of an unencrypted PRX.

https://lolhax.org/2017/09/24/6-61-infinity-an-explanation/

Fixed: since PSP System Software version 6.35.

Lib-PSP iplloader

NMI Backdoor

Found by: Mathieulh, Proxima, C+D/Prometheus - Earliest discovery: 2007-04-04

Introduced: Tachyon 0x00140000 bootrom

Fixed: Never

Applicable to: None

Vulnerable: Lib-PSP iplloader (all bootrom versions, 0.7.0 and newer Kbooti versions, PS Vita's PSP emulator bootrom)

The Lib-PSP iplloader bootrom (present within Tachyon's IC package) as well as Lib-PSP iplloader versions 0.7.0 and onward feature a NMI/Interrupt handler backdoor (most likely used internally for debugging purposes) in its loader part at the very first instructions of the bootrom.

This backdoor allows anyone in control of the memory location address 0xBC100000 to perform a jump to an arbitrary location defined in coprocessor register $9

If value at address 0xBC100000 is not equal to 0 and coprocessor register $9 is set, Lib-PSP iplloader will jump to the address set in the register very early in the code (by the 8th instruction). Else (if value at address 0xBC100000 is equal to 0), coprocessor register $9 will be reset back to 0.

Below are the relevant pieces of code:

ROM:BFC00004                 lw      $v0, 0xBC100000             # store 0xBC100000 to $v0
ROM:BFC0000C                 bnez    $v0, loc_BFC00064           # if $v0 (0xBC100000) is not equal to zero, jump to 0xBFC00064
ROM:BFC00064                 cfc0    $v0, $9                     # store coprocessor $9 to $v0
ROM:BFC00068                 beqz    $v0, loc_BFC00078 $         # if $v0 (coproc $9) is equal to 0 jump to 0xBFC00078
ROM:BFC0006C                 nop
ROM:BFC00070                 jr      $v0                         # jump to register $v0 (value initially set in coproc $9)

This backdoor may allow an attacker performing a hardware based attack to set those values and gain Lib-PSP iplloader time code execution.

Arbitrary IPL Load Address

Found by: C+D/Prometheus - Earliest discovery: 2007-04-04

Introduced: Tachyon 0x00140000 bootrom

Applicable to: IPL time code execution on any PSP. On Tachyon 0x00600000 and later, this implies using SYSREG_RESET_ENABLE_REG (0xBC10004C) as a load address, which will have the CPU jump to the code stored in the the decrypted IPL block that is cached at 0xBFC00000.

Fixed: Partially in Tachyon 0x00600000. The CPU scratchpad (0xA0010000 uncached; 0x80010000 cached) range is now blacklisted, whilst all other addresses remain allowed.

Lib-PSP iplloader will not control the location at which it will load/copy the block. It will happily attempt to perform a memcpy (at a rate of 1 DWORD per cycle) to whatever load address is specified in the IPL header, assuming that the header passes the checks (Kirk cmd 1, Kirk cmd 1 ECDSA, Kirk cmd 0x6C SHA1 (on Tachyon 0x00600000 and later), ...). This allows to write a payload at arbitrary locations.

Arbitrary IPL Entrypoint Address

Found by: C+D/Prometheus - Earliest discovery: 2007-04-04

Introduced: Tachyon 0x00140000 bootrom

Applicable to: IPL time code execution on 01g and 02g, used in Pandora

Fixed: Lib-PSP iplloader 2.6.0

Lib-PSP iplloader will jump to any location specified in the last IPL block's entrypoint. This allows arbitrary execution. This was used in conjunction with the Kirk time-attack to craft a block and gain execution from at address 0xBFD00100 in the Pandora hack, and thus allowed to craft a "valid" block in a more timely fashion.

Note: The vulnerability is also present on Tachyon 0x00600000 and later, but cannot be exploited by itself due to an ECDSA signature (Kirk cmd 17) check.

No minimum IPL block size

Found by: C+D/Prometheus - Earliest discovery: 2007-04-04

Introduced: Tachyon 0x00140000 bootrom

Applicable to: Pandora hack.

Fixed: Tachyon 0x00600000. Bootrom now requires a minimum IPL block size of 0x100.

Lib-PSP iplloader will not control the block size. This allows to craft a small, favorable for time-attack, IPL block.

Lib-PSP iplloader assumes a block with the checksum 0 is the first IPL block

Found by: C+D/Prometheus - Earliest discovery: 2006 Q4

Introduced: Tachyon 0x00140000 bootrom

Applicable to: IPL Code execution on 01g, used to dump the Tachyon bootrom for the first time.

Fixed: indirectly since Tachyon 0x00600000 as no IPL that run on Tachyon 0x00600000 and onwards have a block that uses a previous block checksum of 0 other than block #0 itself.

This implementation fault has been exploited to create a memory hole in VRAM that could be filled with our own payload to gain execution and dump Lib-PSP iplloader.

Lib-PSP iplloader do not perform the XOR step when running in Jig/Service mode

Found by: Mathieulh - Earliest discovery: 2019 Q1

Introduced: Lib-PSP iplloader 3.5.0

Applicable to: Code execution on 3.5.0 Lib-PSP iplloader without previous knowledge of the XOR key.

Fixed: probably never as 3.5.0 is the last known Lib-PSP iplloader revision for Development Tool

This is not so much a vulnerability as a poor design implementation.

To allow service centers to use a unique Memory Stick for multiple PSP models during servicing, Lib-PSP iplloader deliberately disables the XOR step, allowing a non XORed IPL to run from Memory Stick. This is done so that the IPL can run on all systems from 01g to 11g. This is also presumably done because XOR keys may differ in between Tachyon revisions.

This allows a potential attacker with the ability to enable Jig mode on a targeted PSP to bypass the XOR step and thus not requiring to know the XOR key to gain execution at IPL time assuming that all other checks (Kirk cmd 1, Kirk cmd 1 ECDSA, Kirk cmd 0x6C SHA1 (on Tachyon 0x00600000 and later), ...) are passed.

Lib-PSP iplloader clears the XOR key after doing a cache sync during normal execution

Found by: Proxima - Earliest discovery: 2020-01-27

Introduced: Lib-PSP iplloader 3.5.0

Applicable to: Dumping the Lib-PSP iplloader 3.5.0 XOR key from Jig mode execution when used in conjunction with the arbitrary load address vulnerability

Fixed: probably never as 3.5.0 is the last known Lib-PSP iplloader revision for Development Tool

3.5.0 Lib-PSP iplloader clears the XOR key after doing a cache sync during normal execution. This allows to retrieve the key from the uncached memory at address 0xA001088C.

In Jig mode execution, the key is cleared much earlier, however resulting in the cache being synced once the key is already gone. This allows to easily retrieve the key using a XORed IPL block loaded at address 0xBFE01000.

While it may be possible that Tachyon 0x00600000 and later Lib-PSP iplloader fix this issue, it is irrelevant because the code should remain accessible as part of the Tachyon bootrom at address 0xBFC00000)

Faulty ECDSA Hash Comparison

Found by: Davee - Earliest discovery: 2021-02-12

Introduced: Tachyon 0x00600000 bootrom

Applicable to: IPL code execution.

Fixed: never

Starting with Tachyon 0x00600000, Lib-PSP iplloader XORs each IPL block hash as they are loaded, and then uses this final XOR to verify the signature.

This means that inserting two identical blocks in the chain will cancel the XOR change and the signature will remain valid.

NOTE: For this to work, the block checksum of the inserted blocks has to be "forged" so that it matches the one of the previous block checksum

General writeups

https://wololo.net/2014/01/18/10-days-of-hacking-day-4-the-psp-part-1/

https://wololo.net/2014/01/18/10-days-of-hacking-day-5-the-psp-part-2/

https://www.slideshare.net/ruyor/beginners-guide-to-psp-v50-slideshare-edit

https://github.com/BASLQC/BASLQC/wiki/PSP-Custom-Firmware-History#History_of_homebrew_on_PSP