Linux: Double Free
CVE-2024-27433 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 de3340533bd68a7b3d6be1841b8eb3fa6c762fe6, f3633fed984f1db106ff737a0bb52fadb2d89ac7, fa761ce7a1d15cca1a306b3635f81a22b15fee5b 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 0.23% 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 de3340533bd68a7b3d6be1841b8eb3fa6c762fe6 or f3633fed984f1db106ff737a0bb52fadb2d89ac7 or fa761ce7a1d15cca1a306b3635f81a22b15fee5b or a32e88f2b20259f5fe4f8eed598bbc85dc4879ed, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.23 or 6.7.11 or 6.8.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | c50e2ea6507bcf5a4475f821fc03dd1fdcb894a7 up to, but not including, de3340533bd68a7b3d6be1841b8eb3fa6c762fe6; c50e2ea6507bcf5a4475f821fc03dd1fdcb894a7 up to, but not including, f3633fed984f1db106ff737a0bb52fadb2d89ac7; c50e2ea6507bcf5a4475f821fc03dd1fdcb894a7 up to, but not including, fa761ce7a1d15cca1a306b3635f81a22b15fee5b; c50e2ea6507bcf5a4475f821fc03dd1fdcb894a7 up to, but not including, a32e88f2b20259f5fe4f8eed598bbc85dc4879ed; 6.4 | de3340533bd68a7b3d6be1841b8eb3fa6c762fe6, f3633fed984f1db106ff737a0bb52fadb2d89ac7, fa761ce7a1d15cca1a306b3635f81a22b15fee5b, a32e88f2b20259f5fe4f8eed598bbc85dc4879ed |
| Linux | Linux Kernel | 6.4 up to, but not including, 6.6.23; 6.7 up to, but not including, 6.7.11; 6.8 up to, but not including, 6.8.2 | 6.6.23, 6.7.11, 6.8.2 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: mt7622-apmixedsys: Fix an error handling path in clk_mt8135_apmixed_probe() 'clk_data' is allocated with mtk_devm_alloc_clk_data(). So calling mtk_free_clk_data() explicitly in the remove function would lead to a double-free. Remove the redundant call.
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
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
Spotted an error? Tell us.