Linux: Use After Free
CVE-2024-26582 is a high-severity use after free 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 20b4ed034872b4d024b26e2bc1092c3f80e5db96, d684763534b969cca1022e2a28645c7cc91f7fa5, 754c9bab77a1b895b97bd99d754403c505bc79df 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 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 20b4ed034872b4d024b26e2bc1092c3f80e5db96 or d684763534b969cca1022e2a28645c7cc91f7fa5 or 754c9bab77a1b895b97bd99d754403c505bc79df or 32b55c5ff9103b8508c1e04bfa5a08c64e7a925f, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.79 or 6.6.18 or 6.7.6, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | fd31f3996af2627106e22a9f8072764fede51161 up to, but not including, 20b4ed034872b4d024b26e2bc1092c3f80e5db96; fd31f3996af2627106e22a9f8072764fede51161 up to, but not including, d684763534b969cca1022e2a28645c7cc91f7fa5; fd31f3996af2627106e22a9f8072764fede51161 up to, but not including, 754c9bab77a1b895b97bd99d754403c505bc79df; fd31f3996af2627106e22a9f8072764fede51161 up to, but not including, 32b55c5ff9103b8508c1e04bfa5a08c64e7a925f; 6.0 | 20b4ed034872b4d024b26e2bc1092c3f80e5db96, d684763534b969cca1022e2a28645c7cc91f7fa5, 754c9bab77a1b895b97bd99d754403c505bc79df, 32b55c5ff9103b8508c1e04bfa5a08c64e7a925f |
| Linux | Linux Kernel | 6.0 up to, but not including, 6.1.79; 6.2.0 up to, but not including, 6.6.18; 6.7.0 up to, but not including, 6.7.6 | 6.1.79, 6.6.18, 6.7.6 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: net: tls: fix use-after-free with partial reads and async decrypt tls_decrypt_sg doesn't take a reference on the pages from clear_skb, so the put_page() in tls_decrypt_done releases them, and we trigger a use-after-free in process_rx_list when we try to read from the partially-read skb.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.1 High severity
- 9.1 Critical severity
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