Linux: Double Free
CVE-2024-42138 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 ab557f5cd993a3201b09593633d04b891263d5c0, f8b55a465b0e8a500179808166fe9420f5c091a1, 9af7437669b72f804fc4269f487528dbbed142a2 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 ab557f5cd993a3201b09593633d04b891263d5c0 or f8b55a465b0e8a500179808166fe9420f5c091a1 or 9af7437669b72f804fc4269f487528dbbed142a2 or 8ce34dccbe8fa7d2ef86f2d8e7db2a9b67cabfc3, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.98 or 6.6.39 or 6.9.9, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | b217127e5e4ee0ecfce7c5f84cfe082238123bda up to, but not including, ab557f5cd993a3201b09593633d04b891263d5c0; b217127e5e4ee0ecfce7c5f84cfe082238123bda up to, but not including, f8b55a465b0e8a500179808166fe9420f5c091a1; b217127e5e4ee0ecfce7c5f84cfe082238123bda up to, but not including, 9af7437669b72f804fc4269f487528dbbed142a2; b217127e5e4ee0ecfce7c5f84cfe082238123bda up to, but not including, 8ce34dccbe8fa7d2ef86f2d8e7db2a9b67cabfc3; 5.19 | ab557f5cd993a3201b09593633d04b891263d5c0, f8b55a465b0e8a500179808166fe9420f5c091a1, 9af7437669b72f804fc4269f487528dbbed142a2, 8ce34dccbe8fa7d2ef86f2d8e7db2a9b67cabfc3 |
| Linux | Linux Kernel | 5.19 up to, but not including, 6.1.98; 6.2 up to, but not including, 6.6.39; 6.7 up to, but not including, 6.9.9; 6.10 | 6.1.98, 6.6.39, 6.9.9 |
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: mlxsw: core_linecards: Fix double memory deallocation in case of invalid INI file In case of invalid INI file mlxsw_linecard_types_init() deallocates memory but doesn't reset pointer to NULL and returns 0. In case of any error occurred after mlxsw_linecard_types_init() call, mlxsw_linecards_init() calls mlxsw_linecard_types_fini() which performs memory deallocation again. Add pointer reset to NULL. Found by Linux Verification Center (linuxtesting.org) with SVACE.
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
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
- 7.8 High severity
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