Linux: Use After Free
CVE-2024-53179 is a high-severity use after 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 0944c2596c2a3442735b5bb6714a17a16188a68f, 39619c65ab4bbb3e78c818f537687653e112764d, 0e2b654a3848bf9da3b0d54c1ccf3f1b8c635591 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 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 0944c2596c2a3442735b5bb6714a17a16188a68f or 39619c65ab4bbb3e78c818f537687653e112764d or 0e2b654a3848bf9da3b0d54c1ccf3f1b8c635591 or 343d7fe6df9e247671440a932b6a73af4fa86d95, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.70 or 6.12.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 32811d242ff6f28da2ab18c90a15e32fd958e774 up to, but not including, 0944c2596c2a3442735b5bb6714a17a16188a68f; 32811d242ff6f28da2ab18c90a15e32fd958e774 up to, but not including, 39619c65ab4bbb3e78c818f537687653e112764d; 32811d242ff6f28da2ab18c90a15e32fd958e774 up to, but not including, 0e2b654a3848bf9da3b0d54c1ccf3f1b8c635591; 32811d242ff6f28da2ab18c90a15e32fd958e774 up to, but not including, 343d7fe6df9e247671440a932b6a73af4fa86d95; 3.12 | 0944c2596c2a3442735b5bb6714a17a16188a68f, 39619c65ab4bbb3e78c818f537687653e112764d, 0e2b654a3848bf9da3b0d54c1ccf3f1b8c635591, 343d7fe6df9e247671440a932b6a73af4fa86d95 |
| Linux | Linux Kernel | before 6.6.70; 6.7 up to, but not including, 6.12.2 | 6.6.70, 6.12.2 |
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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | 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: smb: client: fix use-after-free of signing key Customers have reported use-after-free in @ses->auth_key.response with SMB2.1 + sign mounts which occurs due to following race: task A task B cifs_mount() dfs_mount_share() get_session() cifs_mount_get_session() cifs_send_recv() cifs_get_smb_ses() compound_send_recv() cifs_setup_session() smb2_setup_request() kfree_sensitive() smb2_calc_signature() crypto_shash_setkey() *UAF* Fix this by ensuring that we have a valid @ses->auth_key.response by checking whether @ses->ses_status is SES_GOOD or SES_EXITING with @ses->ses_lock held. After commit 24a9799aa8ef ("smb: client: fix UAF in smb2_reconnect_server()"), we made sure to call ->logoff() only when @ses was known to be good (e.g. valid ->auth_key.response), so it's safe to access signing key when @ses->ses_status == SES_EXITING.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
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 Use After Free vulnerabilities
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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