Linux: Use After Free
CVE-2024-50264 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 5f092a4271f6dccf88fe0d132475a17b69ef71df, fd8ae346692a56b4437d626c5460c7104980f389, eb1bdcb7dfc30b24495ee4c5533af0ed135cb5f1 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 0.35% 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 5f092a4271f6dccf88fe0d132475a17b69ef71df or fd8ae346692a56b4437d626c5460c7104980f389 or eb1bdcb7dfc30b24495ee4c5533af0ed135cb5f1 or 2a6a4e69f255b7aed17f93995691ab4f0d3c2203, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.19.324 or 5.4.286 or 5.10.230 or 5.15.172, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, 5f092a4271f6dccf88fe0d132475a17b69ef71df; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, fd8ae346692a56b4437d626c5460c7104980f389; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, eb1bdcb7dfc30b24495ee4c5533af0ed135cb5f1; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, 2a6a4e69f255b7aed17f93995691ab4f0d3c2203; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, 44d29897eafd0e1196453d3003a4d5e0b968eeab; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, b110196fec44fe966952004bd426967c2a8fd358; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, 5f970935d09934222fdef3d0e20c648ea7a963c1; 06a8fc78367d070720af960dcecec917d3ae5f3b up to, but not including, 6ca575374dd9a507cdd16dfa0e78c2e9e20bd05f; and 1 more ranges | 5f092a4271f6dccf88fe0d132475a17b69ef71df, fd8ae346692a56b4437d626c5460c7104980f389, eb1bdcb7dfc30b24495ee4c5533af0ed135cb5f1, 2a6a4e69f255b7aed17f93995691ab4f0d3c2203, 44d29897eafd0e1196453d3003a4d5e0b968eeab, b110196fec44fe966952004bd426967c2a8fd358 |
| Linux | Linux Kernel | 4.8 up to, but not including, 4.19.324; 4.20 up to, but not including, 5.4.286; 5.5 up to, but not including, 5.10.230; 5.11 up to, but not including, 5.15.172; 5.16 up to, but not including, 6.1.117; 6.2 up to, but not including, 6.6.61; 6.7 up to, but not including, 6.11.8; 6.12 | 4.19.324, 5.4.286, 5.10.230, 5.15.172, 6.1.117, 6.6.61 |
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 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: Initialization of the dangling pointer occurring in vsk->trans During loopback communication, a dangling pointer can be created in vsk->trans, potentially leading to a Use-After-Free condition. This issue is resolved by initializing vsk->trans to NULL.
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
- git.kernel.org/stable/c/2a6a4e69f255b7aed17f93995691ab4f0d3c2203
- git.kernel.org/stable/c/44d29897eafd0e1196453d3003a4d5e0b968eeab
- git.kernel.org/stable/c/5f092a4271f6dccf88fe0d132475a17b69ef71df
- git.kernel.org/stable/c/6ca575374dd9a507cdd16dfa0e78c2e9e20bd05f
- git.kernel.org/stable/c/b110196fec44fe966952004bd426967c2a8fd358
- git.kernel.org/stable/c/eb1bdcb7dfc30b24495ee4c5533af0ed135cb5f1
- git.kernel.org/stable/c/fd8ae346692a56b4437d626c5460c7104980f389
Other references
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
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