Linux: Double Free
CVE-2023-52667 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 72a729868592752b5a294d27453da264106983b1, b2fa86b2aceb4bc9ada51cea90f61546d7512cbe, 2897c981ee63e1be5e530b1042484626a10b26d8 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 72a729868592752b5a294d27453da264106983b1 or b2fa86b2aceb4bc9ada51cea90f61546d7512cbe or 2897c981ee63e1be5e530b1042484626a10b26d8 or 65a4ade8a6d205979292e88beeb6a626ddbd4779, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.149 or 6.1.76 or 6.6.15 or 6.7.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0f575c20bf0686caf3d82d6c626c2e1e4a4c36e6 up to, but not including, 72a729868592752b5a294d27453da264106983b1; 0f575c20bf0686caf3d82d6c626c2e1e4a4c36e6 up to, but not including, b2fa86b2aceb4bc9ada51cea90f61546d7512cbe; 0f575c20bf0686caf3d82d6c626c2e1e4a4c36e6 up to, but not including, 2897c981ee63e1be5e530b1042484626a10b26d8; 0f575c20bf0686caf3d82d6c626c2e1e4a4c36e6 up to, but not including, 65a4ade8a6d205979292e88beeb6a626ddbd4779; 0f575c20bf0686caf3d82d6c626c2e1e4a4c36e6 up to, but not including, aef855df7e1bbd5aa4484851561211500b22707e; 5.13 | 72a729868592752b5a294d27453da264106983b1, b2fa86b2aceb4bc9ada51cea90f61546d7512cbe, 2897c981ee63e1be5e530b1042484626a10b26d8, 65a4ade8a6d205979292e88beeb6a626ddbd4779, aef855df7e1bbd5aa4484851561211500b22707e |
| Linux | Linux Kernel | 5.13 up to, but not including, 5.15.149; 5.16 up to, but not including, 6.1.76; 6.2 up to, but not including, 6.6.15; 6.7 up to, but not including, 6.7.3; 6.8 | 5.15.149, 6.1.76, 6.6.15, 6.7.3 |
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
- 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: net/mlx5e: fix a potential double-free in fs_any_create_groups When kcalloc() for ft->g succeeds but kvzalloc() for in fails, fs_any_create_groups() will free ft->g. However, its caller fs_any_create_table() will free ft->g again through calling mlx5e_destroy_flow_table(), which will lead to a double-free. Fix this by setting ft->g to NULL in fs_any_create_groups().
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/2897c981ee63e1be5e530b1042484626a10b26d8
- git.kernel.org/stable/c/65a4ade8a6d205979292e88beeb6a626ddbd4779
- git.kernel.org/stable/c/72a729868592752b5a294d27453da264106983b1
- git.kernel.org/stable/c/aef855df7e1bbd5aa4484851561211500b22707e
- git.kernel.org/stable/c/b2fa86b2aceb4bc9ada51cea90f61546d7512cbe
Recent Double 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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