Vulnerabilities

Kernel

PSP kernel exploits

sceNetMCopyback kexploit by qwikrazor87 and AcidSnake (ARK-4): PSP ?.?? https://github.com/PSP-Archive/ARK-4/blob/main/loader/live/kernel/rodumper/main.c

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

sceHttpStorageOpen kexploit, 0xFFFFFFFFailSploit, write -1 to anywhere by some1 (Chronoswitch): PSP 6.38-6.39

sceUtilityPowerRegisterCallback kexploit by TN and davee with sceKernelUtilsMd5BlockInit kexploit to keep the data dynamic (TN-HEN, Chronoswitch): PSP 6.20, 6.31, 6.35

ifhandle 5.70 race condition by davee: PSP <= 5.70, patched on PSP 6.20

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

registry error store: PSP <=2.80

LoadExec buffer overflow: PSP <=2.60

reused index.dat key: PSP 2.00, 2.01

swaptrick/kxploit: PSP <=1.50

kernel flagged ELF: PSP <=1.00

PS Vita ePSP kernel exploits

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

kernel read using sceNpCore_8AFAB4A0 Double-fetch Race Condition kexploit by qwikrazor87 (Trinity): PS Vita 3.70 https://theofficialflow.github.io/2019/06/18/trinity.html#double-fetch-race-condition

VPL kexploit: PS Vita 3.00-3.52

sceKernelDeleteThread kexploit: PS Vita <=3.50

sceVideocodec kexploit: PS Vita 3.30-3.36

_sceSdGetLastIndex kexploit (TN-X, TN-V): PS Vita <=3.20 (works on 3.18-3.20)

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

sceWlanGetEtherAddr kexploit: PS Vita 1.61-1.80

_sceG729EncodeTermResource kexploit: PS Vita FW unk

sceWlanDrv kexploit: PS Vita FW unk

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