Linux: Use After Free
CVE-2024-44974 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 ddee5b4b6a1cc03c1e9921cf34382e094c2009f1, f2c865e9e3ca44fc06b5f73b29a954775e4dbb38, 2b4f46f9503633dade75cb796dd1949d0e6581a1 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 0.27% 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 ddee5b4b6a1cc03c1e9921cf34382e094c2009f1 or f2c865e9e3ca44fc06b5f73b29a954775e4dbb38 or 2b4f46f9503633dade75cb796dd1949d0e6581a1 or 9a9afbbc3fbfca4975eea4aa5b18556db5a0c0b8, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.226 or 5.15.167 or 6.1.109 or 6.6.48, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 up to, but not including, ddee5b4b6a1cc03c1e9921cf34382e094c2009f1; 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 up to, but not including, f2c865e9e3ca44fc06b5f73b29a954775e4dbb38; 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 up to, but not including, 2b4f46f9503633dade75cb796dd1949d0e6581a1; 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 up to, but not including, 9a9afbbc3fbfca4975eea4aa5b18556db5a0c0b8; 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 up to, but not including, 0201d65d9806d287a00e0ba96f0321835631f63f; 01cacb00b35cb62b139f07d5f84bcf0eeda8eff6 up to, but not including, 48e50dcbcbaaf713d82bf2da5c16aeced94ad07d; 5.7 | ddee5b4b6a1cc03c1e9921cf34382e094c2009f1, f2c865e9e3ca44fc06b5f73b29a954775e4dbb38, 2b4f46f9503633dade75cb796dd1949d0e6581a1, 9a9afbbc3fbfca4975eea4aa5b18556db5a0c0b8, 0201d65d9806d287a00e0ba96f0321835631f63f, 48e50dcbcbaaf713d82bf2da5c16aeced94ad07d |
| Debian | Debian Linux | 11.0 | Not stated |
| Linux | Linux Kernel | 5.7 up to, but not including, 5.10.226; 5.11 up to, but not including, 5.15.167; 5.16 up to, but not including, 6.1.109; 6.2 up to, but not including, 6.6.48; 6.7 up to, but not including, 6.10.7; 6.11 | 5.10.226, 5.15.167, 6.1.109, 6.6.48, 6.10.7 |
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 | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: avoid possible UaF when selecting endp select_local_address() and select_signal_address() both select an endpoint entry from the list inside an RCU protected section, but return a reference to it, to be read later on. If the entry is dereferenced after the RCU unlock, reading info could cause a Use-after-Free. A simple solution is to copy the required info while inside the RCU protected section to avoid any risk of UaF later. The address ID might need to be modified later to handle the ID0 case later, so a copy seems OK to deal with.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/0201d65d9806d287a00e0ba96f0321835631f63f
- git.kernel.org/stable/c/2b4f46f9503633dade75cb796dd1949d0e6581a1
- git.kernel.org/stable/c/48e50dcbcbaaf713d82bf2da5c16aeced94ad07d
- git.kernel.org/stable/c/9a9afbbc3fbfca4975eea4aa5b18556db5a0c0b8
- git.kernel.org/stable/c/ddee5b4b6a1cc03c1e9921cf34382e094c2009f1
- git.kernel.org/stable/c/f2c865e9e3ca44fc06b5f73b29a954775e4dbb38
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2024/10/msg00003.htmlMailing List, Third Party Advisory
- lists.debian.org/debian-lts-announce/2025/01/msg00001.htmlMailing List, Third Party Advisory
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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