Linux: Double Free
CVE-2024-50215 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 c94e965f766321641ec38e4eece9ce8884543244, c60af16e1d6cc2237d58336546d6adfc067b6b8f, e61bd51e44409495d75847e9230736593e4c8710 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 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to c94e965f766321641ec38e4eece9ce8884543244 or c60af16e1d6cc2237d58336546d6adfc067b6b8f or e61bd51e44409495d75847e9230736593e4c8710 or d2f551b1f72b4c508ab9298419f6feadc3b5d791, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.116 or 6.6.60 or 6.11.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7a277c37d3522e9b2777d762bbbcecafae2b1f8d up to, but not including, c94e965f766321641ec38e4eece9ce8884543244; 7a277c37d3522e9b2777d762bbbcecafae2b1f8d up to, but not including, c60af16e1d6cc2237d58336546d6adfc067b6b8f; 7a277c37d3522e9b2777d762bbbcecafae2b1f8d up to, but not including, e61bd51e44409495d75847e9230736593e4c8710; 7a277c37d3522e9b2777d762bbbcecafae2b1f8d up to, but not including, d2f551b1f72b4c508ab9298419f6feadc3b5d791; 6.0 | c94e965f766321641ec38e4eece9ce8884543244, c60af16e1d6cc2237d58336546d6adfc067b6b8f, e61bd51e44409495d75847e9230736593e4c8710, d2f551b1f72b4c508ab9298419f6feadc3b5d791 |
| Linux | Linux Kernel | 6.0 up to, but not including, 6.1.116; 6.2 up to, but not including, 6.6.60; 6.7 up to, but not including, 6.11.7; 6.12 | 6.1.116, 6.6.60, 6.11.7 |
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 | 8.1 | 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: nvmet-auth: assign dh_key to NULL after kfree_sensitive ctrl->dh_key might be used across multiple calls to nvmet_setup_dhgroup() for the same controller. So it's better to nullify it after release on error path in order to avoid double free later in nvmet_destroy_auth(). 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: total).
- 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
- 7.4 High severity
- 7.8 High severity
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