Linux: Out-of-bounds Read
CVE-2025-21743 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 18bf6f5cce3172cb303c3f0551aa9443d5ed74f8, d677e7dd59ad6837496f5a02d8e5d39824278dfd, d824a964185910e317287f034c0a439c08b4fe49 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 0.22% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 18bf6f5cce3172cb303c3f0551aa9443d5ed74f8 or d677e7dd59ad6837496f5a02d8e5d39824278dfd or d824a964185910e317287f034c0a439c08b4fe49 or c219427ed296f94bb4b91d08626776dc7719ee27, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.78 or 6.12.14 or 6.13.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, 18bf6f5cce3172cb303c3f0551aa9443d5ed74f8; a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, d677e7dd59ad6837496f5a02d8e5d39824278dfd; a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, d824a964185910e317287f034c0a439c08b4fe49; a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, c219427ed296f94bb4b91d08626776dc7719ee27; 6.5 | 18bf6f5cce3172cb303c3f0551aa9443d5ed74f8, d677e7dd59ad6837496f5a02d8e5d39824278dfd, d824a964185910e317287f034c0a439c08b4fe49, c219427ed296f94bb4b91d08626776dc7719ee27 |
| Linux | Linux Kernel | 6.5 up to, but not including, 6.6.78; 6.7 up to, but not including, 6.12.14; 6.13 up to, but not including, 6.13.3 | 6.6.78, 6.12.14, 6.13.3 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.1 | High | NVD |
| CVSS 3.1 | 7.1 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: usbnet: ipheth: fix possible overflow in DPE length check Originally, it was possible for the DPE length check to overflow if wDatagramIndex + wDatagramLength > U16_MAX. This could lead to an OoB read. Move the wDatagramIndex term to the other side of the inequality. An existing condition ensures that wDatagramIndex < urb->actual_length.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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