CyberSecBulletin
CVE-2025-38676NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2025-38676 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 a732502bf3bbe859613b6d7b2b0313b11f0474ac, 0ad8509b468fa1058f4f400a1829f29e4ccc4de8, 9ff52d3af0ef286535749e14e3fe9eceb39a8349 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 0.42% 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 a732502bf3bbe859613b6d7b2b0313b11f0474ac or 0ad8509b468fa1058f4f400a1829f29e4ccc4de8 or 9ff52d3af0ef286535749e14e3fe9eceb39a8349 or 8f80c633cba144f721d38d9380f23d23ab7db10e, whichever matches your release line, or a later version.
  2. Update SIMATIC CN 4100 to V5.0 or a later version.
  3. Update Linux Kernel to 5.5 or 5.10.241 or 5.15.190 or 6.1.149, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxf2a5ec7f7b28f9b9cd5fac232ff51019a7f7b9e9 up to, but not including, a732502bf3bbe859613b6d7b2b0313b11f0474ac; c513043e0afe6a8ba79d00af358655afabb576d2 up to, but not including, 0ad8509b468fa1058f4f400a1829f29e4ccc4de8; 2ae19ac3ea82a5b87a81c10adbb497c9e58bdd60 up to, but not including, 9ff52d3af0ef286535749e14e3fe9eceb39a8349; b6b26d86c61c441144c72f842f7469bb686e1211 up to, but not including, 8f80c633cba144f721d38d9380f23d23ab7db10e; b6b26d86c61c441144c72f842f7469bb686e1211 up to, but not including, 4bdb0f78bddbfa77d3ab458a21dd9cec495d317a; b6b26d86c61c441144c72f842f7469bb686e1211 up to, but not including, 736db11c86f03e717fc4bf771d05efdf10d23acb; b6b26d86c61c441144c72f842f7469bb686e1211 up to, but not including, 8503d0fcb1086a7cfe26df67ca4bd9bd9e99bdec; 5e97dc748d13fad582136ba0c8cec215c7aeeb17; and 7 more rangesa732502bf3bbe859613b6d7b2b0313b11f0474ac, 0ad8509b468fa1058f4f400a1829f29e4ccc4de8, 9ff52d3af0ef286535749e14e3fe9eceb39a8349, 8f80c633cba144f721d38d9380f23d23ab7db10e, 4bdb0f78bddbfa77d3ab458a21dd9cec495d317a, 736db11c86f03e717fc4bf771d05efdf10d23acb
SiemensSIMATIC CN 4100before V5.0V5.0
LinuxLinux Kernel5.4.237 up to, but not including, 5.5; 5.10.175 up to, but not including, 5.10.241; 5.15.103 up to, but not including, 5.15.190; 6.1.16 up to, but not including, 6.1.149; 6.2.3 up to, but not including, 6.6.103; 6.7 up to, but not including, 6.12.44; 6.13 up to, but not including, 6.16.4; 6.175.5, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.44
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.

Official description

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Avoid stack buffer overflow from kernel cmdline While the kernel command line is considered trusted in most environments, avoid writing 1 byte past the end of "acpiid" if the "str" argument is maximum length.

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. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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