Linux: Double Free
CVE-2024-56704 is a high-severity double 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 692eb06703afc3e24d889d77e94a0e20229f6a4a, d74b4b297097bd361b8a9abfde9b521ff464ea9c, 7f5a2ed5c1810661e6b03f5a4ebf17682cdea850 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 0.24% 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 692eb06703afc3e24d889d77e94a0e20229f6a4a or d74b4b297097bd361b8a9abfde9b521ff464ea9c or 7f5a2ed5c1810661e6b03f5a4ebf17682cdea850 or 4950408793b118cb8075bcee1f033b543fb719fa, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.19.325 or 5.4.287 or 5.10.231 or 5.15.174, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, 692eb06703afc3e24d889d77e94a0e20229f6a4a; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, d74b4b297097bd361b8a9abfde9b521ff464ea9c; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, 7f5a2ed5c1810661e6b03f5a4ebf17682cdea850; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, 4950408793b118cb8075bcee1f033b543fb719fa; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, b9e26059664bd9ebc64a0e8f5216266fc9f84265; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, 2bb3ee1bf237557daea1d58007d2e1d4a6502ccf; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, d888f5f5d76b2722c267e6bdf51d445d60647b7b; 71ebd71921e451f0f942ddfe85d01e31ddc6eb88 up to, but not including, 530bc9f03a102fac95b07cda513bfc16ff69e0ee; and 2 more ranges | 692eb06703afc3e24d889d77e94a0e20229f6a4a, d74b4b297097bd361b8a9abfde9b521ff464ea9c, 7f5a2ed5c1810661e6b03f5a4ebf17682cdea850, 4950408793b118cb8075bcee1f033b543fb719fa, b9e26059664bd9ebc64a0e8f5216266fc9f84265, 2bb3ee1bf237557daea1d58007d2e1d4a6502ccf |
| Linux | Linux Kernel | 4.12 up to, but not including, 4.19.325; 4.20 up to, but not including, 5.4.287; 5.5 up to, but not including, 5.10.231; 5.11 up to, but not including, 5.15.174; 5.16 up to, but not including, 6.1.120; 6.2 up to, but not including, 6.6.64; 6.7 up to, but not including, 6.11.11; 6.12 up to, but not including, 6.12.2 | 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64 |
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 | 8.4 | High | CNA |
| 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: 9p/xen: fix release of IRQ Kernel logs indicate an IRQ was double-freed. Pass correct device ID during IRQ release. [Dominique: remove confusing variable reset to 0]
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
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/2bb3ee1bf237557daea1d58007d2e1d4a6502ccf
- git.kernel.org/stable/c/4950408793b118cb8075bcee1f033b543fb719fa
- git.kernel.org/stable/c/530bc9f03a102fac95b07cda513bfc16ff69e0ee
- git.kernel.org/stable/c/692eb06703afc3e24d889d77e94a0e20229f6a4a
- git.kernel.org/stable/c/7f5a2ed5c1810661e6b03f5a4ebf17682cdea850
- git.kernel.org/stable/c/b9e26059664bd9ebc64a0e8f5216266fc9f84265
- git.kernel.org/stable/c/d74b4b297097bd361b8a9abfde9b521ff464ea9c
- git.kernel.org/stable/c/d888f5f5d76b2722c267e6bdf51d445d60647b7b
- git.kernel.org/stable/c/e43c608f40c065b30964f0a806348062991b802d
Other references
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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