Linux: Out-of-bounds Read
CVE-2025-21742 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 8fb062178e1ce180e2cfdc9abc83a1b9fea381ca, cf1ac7f7cf601ac31d1580559c002b5e37b733b7, 2b619445dcb6dab97d8ed033fb57225aca1288c4 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 8fb062178e1ce180e2cfdc9abc83a1b9fea381ca or cf1ac7f7cf601ac31d1580559c002b5e37b733b7 or 2b619445dcb6dab97d8ed033fb57225aca1288c4 or 86586dcb75cb8fd062a518aca8ee667938b91efb, 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, 8fb062178e1ce180e2cfdc9abc83a1b9fea381ca; a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, cf1ac7f7cf601ac31d1580559c002b5e37b733b7; a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, 2b619445dcb6dab97d8ed033fb57225aca1288c4; a2d274c62e44b1995c170595db3865c6fe701226 up to, but not including, 86586dcb75cb8fd062a518aca8ee667938b91efb; 6.5 | 8fb062178e1ce180e2cfdc9abc83a1b9fea381ca, cf1ac7f7cf601ac31d1580559c002b5e37b733b7, 2b619445dcb6dab97d8ed033fb57225aca1288c4, 86586dcb75cb8fd062a518aca8ee667938b91efb |
| 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: use static NDP16 location in URB Original code allowed for the start of NDP16 to be anywhere within the URB based on the `wNdpIndex` value in NTH16. Only the start position of NDP16 was checked, so it was possible for even the fixed-length part of NDP16 to extend past the end of URB, leading to an out-of-bounds read. On iOS devices, the NDP16 header always directly follows NTH16. Rely on and check for this specific format. This, along with NCM-specific minimal URB length check that already exists, will ensure that the fixed-length part of NDP16 plus a set amount of DPEs fit within the URB. Note that this commit alone does not fully address the OoB read. The limit on the amount of DPEs needs to be enforced separately.
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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