CyberSecBulletin
CVE-2025-38730NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2025-38730 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 3b53dc1c641f2884d4750fc25aaf6c36b90db606, fe9da1812f8697a38f7e30991d568ec199e16059, 21a4ddb0f5e933f372808c10b9ac704505751bb1 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 0.17% 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 3b53dc1c641f2884d4750fc25aaf6c36b90db606 or fe9da1812f8697a38f7e30991d568ec199e16059 or 21a4ddb0f5e933f372808c10b9ac704505751bb1 or 2eb7937b5fc7fcd90eab7bebb0181214b61b9283, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.103 or 6.12.44 or 6.15.11 or 6.16.2, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxc56e022c0a27142b7b59ae6bdf45f86bf4b298a1 up to, but not including, 3b53dc1c641f2884d4750fc25aaf6c36b90db606; c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 up to, but not including, fe9da1812f8697a38f7e30991d568ec199e16059; c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 up to, but not including, 21a4ddb0f5e933f372808c10b9ac704505751bb1; c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 up to, but not including, 2eb7937b5fc7fcd90eab7bebb0181214b61b9283; c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 up to, but not including, 41b70df5b38bc80967d2e0ed55cc3c3896bba781; 6.43b53dc1c641f2884d4750fc25aaf6c36b90db606, fe9da1812f8697a38f7e30991d568ec199e16059, 21a4ddb0f5e933f372808c10b9ac704505751bb1, 2eb7937b5fc7fcd90eab7bebb0181214b61b9283, 41b70df5b38bc80967d2e0ed55cc3c3896bba781
LinuxLinux Kernel6.4 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, 6.15.11; 6.16 up to, but not including, 6.16.2; 6.176.6.103, 6.12.44, 6.15.11, 6.16.2

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: io_uring/net: commit partial buffers on retry Ring provided buffers are potentially only valid within the single execution context in which they were acquired. io_uring deals with this and invalidates them on retry. But on the networking side, if MSG_WAITALL is set, or if the socket is of the streaming type and too little was processed, then it will hang on to the buffer rather than recycle or commit it. This is problematic for two reasons: 1) If someone unregisters the provided buffer ring before a later retry, then the req->buf_list will no longer be valid. 2) If multiple sockers are using the same buffer group, then multiple receives can consume the same memory. This can cause data corruption in the application, as either receive could land in the same userspace buffer. Fix this by disallowing partial retries from pinning a provided buffer across multiple executions, if ring provided buffers are used.

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: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

Spotted an error? Tell us.