CVE-2023-53331 [High] | Out-of-bounds Write in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: pstore/ram: Check start of empty przs during init After commit 30696378f68a ("pstore/ram: Do not treat empty buffers as valid"), initialization would assume a prz was valid after seeing that the buffer_size is zero (regardless of the buffer start position). This unchecked start value means it could be outside the bounds of the buffer, leading to future access panics when written to: sysdump_panic_event+0x3b4/0x5b8 atomic_notifier_call_chain+0x54/0x90 panic+0x1c8/0x42c die+0x29c/0x2a8 die_kernel_fault+0x68/0x78 __do_kernel_fault+0x1c4/0x1e0 do_bad_area+0x40/0x100 do_translation_fault+0x68/0x80 do_mem_abort+0x68/0xf8 el1_da+0x1c/0xc0 __raw_writeb+0x38/0x174 __memcpy_toio+0x40/0xac persistent_ram_update+0x44/0x12c persistent_ram_write+0x1a8/0x1b8 ramoops_pstore_write+0x198/0x1e8 pstore_console_write+0x94/0xe0 ... To avoid this, also check if the prz start is 0 during the initialization phase. If not, the next prz sanity check case will discover it (start > size) and zap the buffer back to a sane state. [kees: update commit log with backtrace and clarifications]

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-09-17	—	0.03%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-09-17

—

0.03%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2023-53331

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2023-53331 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2023-53331
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2023-53331
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2023-53331/
`ubuntu`	medium	CVE-2023-53331 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 161, released 141, not-affected 75, needed 19, needs-triage 1.	https://ubuntu.com/security/CVE-2023-53331

Affected software / configurations for CVE-2023-53331

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 3.18.133, < 3.19	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.4.172, < 4.5	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.9.153, < 4.10	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.14.96, < 4.14.326	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.19.18, < 4.19.295	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.20.5, < 5.4.257	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.195	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.132	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.53	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.4.16	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.5, < 6.5.3	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2023-53331

URL	Tags
https://git.kernel.org/stable/c/25fb4e3402d46f425ec135ef6f09792a4c1b3003	Patch
https://git.kernel.org/stable/c/89312657337e6e03ad6e9ea1a462bd9c158c85c8	Patch
https://git.kernel.org/stable/c/c807ccdd812d18985860504b503899f3140a9549	Patch
https://git.kernel.org/stable/c/dc2f60de9a7d3efd982440117dab5579898d808c	Patch
https://git.kernel.org/stable/c/e95d7a8a6edd14f8fab44c777dd7281db91f6ae2	Patch
https://git.kernel.org/stable/c/e972231db29b5d1dccc13bf9d5ba55b6979a69ed	Patch
https://git.kernel.org/stable/c/f77990358628b01bdc03752126ff5f716ea37615	Patch
https://git.kernel.org/stable/c/fe8c3623ab06603eb760444a032d426542212021	Patch
https://git.kernel.org/stable/c/fedecaeef88899d940b69368c996e8b3b0b8650d	Patch

URL

CVE-2023-53331 | pstore/ram: Check start of empty przs during init

Exploit prediction scoring system (EPSS) score for CVE-2023-53331

Common vulnerability scoring system (CVSS) metrics for CVE-2023-53331

Weakness enumeration for CVE-2023-53331

OS Trackers for CVE-2023-53331

Affected software / configurations for CVE-2023-53331

References for CVE-2023-53331