CyberSecBulletin
CVE-2025-37923NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2025-37923 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions f4b0174e9f18aaba59ee6ffdaf8827a7f94eb606, 665ce421041890571852422487f4c613d1824ba9, 1a3f9482b50b74fa9421bff8ceecfefd0dc06f8f as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to f4b0174e9f18aaba59ee6ffdaf8827a7f94eb606 or 665ce421041890571852422487f4c613d1824ba9 or 1a3f9482b50b74fa9421bff8ceecfefd0dc06f8f or 441021e5b3c7d9bd1b963590652c415929f3b157, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.294 or 5.10.238 or 5.15.182 or 6.1.138, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, f4b0174e9f18aaba59ee6ffdaf8827a7f94eb606; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, 665ce421041890571852422487f4c613d1824ba9; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, 1a3f9482b50b74fa9421bff8ceecfefd0dc06f8f; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, 441021e5b3c7d9bd1b963590652c415929f3b157; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, 056ebbddb8faf4ddf83d005454dd78fc25c2d897; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, 1f27a3e93b8d674b24b27fcdbc6f72743cd96c0d; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, c5d2b66c5ef5037b4b4360e5447605ff00ba1bd4; 3c56819b14b00dd449bd776303e61f8532fad09f up to, but not including, f5178c41bb43444a6008150fe6094497135d07cb; and 1 more rangesf4b0174e9f18aaba59ee6ffdaf8827a7f94eb606, 665ce421041890571852422487f4c613d1824ba9, 1a3f9482b50b74fa9421bff8ceecfefd0dc06f8f, 441021e5b3c7d9bd1b963590652c415929f3b157, 056ebbddb8faf4ddf83d005454dd78fc25c2d897, 1f27a3e93b8d674b24b27fcdbc6f72743cd96c0d
LinuxLinux Kernel2.6.30 up to, but not including, 5.4.294; 5.5 up to, but not including, 5.10.238; 5.11 up to, but not including, 5.15.182; 5.16 up to, but not including, 6.1.138; 6.2 up to, but not including, 6.6.90; 6.7 up to, but not including, 6.12.28; 6.13 up to, but not including, 6.14.6; 6.155.4.294, 5.10.238, 5.15.182, 6.1.138, 6.6.90, 6.12.28
DebianDebian Linux11.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix oob write in trace_seq_to_buffer() syzbot reported this bug: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260 CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 .... ================================================================== It has been reported that trace_seq_to_buffer() tries to copy more data than PAGE_SIZE to buf. Therefore, to prevent this, we should use the smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Recent Out-of-bounds Write vulnerabilities

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