Linux: Use After Free
CVE-2023-53153 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 66af4a2ab1d65d556d638cb9555a3b823c2557a9, a2a92b3e9d8e03ee3f9ee407fc46a9b4bd02d8b6, 6f1959c17d4cb5b74af6fc31dc787e1dc3e4f6e2 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 0.16% 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 66af4a2ab1d65d556d638cb9555a3b823c2557a9 or a2a92b3e9d8e03ee3f9ee407fc46a9b4bd02d8b6 or 6f1959c17d4cb5b74af6fc31dc787e1dc3e4f6e2 or 2cfe78619b0de6d2da773978bc2d22797212eaa7, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.14.308 or 4.19.276 or 5.4.235 or 5.10.173, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, 66af4a2ab1d65d556d638cb9555a3b823c2557a9; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, a2a92b3e9d8e03ee3f9ee407fc46a9b4bd02d8b6; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, 6f1959c17d4cb5b74af6fc31dc787e1dc3e4f6e2; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, 2cfe78619b0de6d2da773978bc2d22797212eaa7; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, fd081afd21eb35b968b0330700c43ec94986e1c4; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, 22dfb21bf1cd876616d45cda1bc6daa89eec6747; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, f4b6a138efb8a32507b8946104e32cb926308da7; fffd0934b9390f34bec45762192b7edd3b12b4b5 up to, but not including, 015b8cc5e7c4d7bb671f1984d7b7338c310b185b; and 1 more ranges | 66af4a2ab1d65d556d638cb9555a3b823c2557a9, a2a92b3e9d8e03ee3f9ee407fc46a9b4bd02d8b6, 6f1959c17d4cb5b74af6fc31dc787e1dc3e4f6e2, 2cfe78619b0de6d2da773978bc2d22797212eaa7, fd081afd21eb35b968b0330700c43ec94986e1c4, 22dfb21bf1cd876616d45cda1bc6daa89eec6747 |
| Linux | Linux Kernel | 2.6.32 up to, but not including, 4.14.308; 4.15 up to, but not including, 4.19.276; 4.20 up to, but not including, 5.4.235; 5.5 up to, but not including, 5.10.173; 5.11 up to, but not including, 5.15.99; 5.16 up to, but not including, 6.1.16; 6.2 up to, but not including, 6.2.3 | 4.14.308, 4.19.276, 5.4.235, 5.10.173, 5.15.99, 6.1.16 |
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: wifi: cfg80211: Fix use after free for wext Key information in wext.connect is not reset on (re)connect and can hold data from a previous connection. Reset key data to avoid that drivers or mac80211 incorrectly detect a WEP connection request and access the freed or already reused memory. Additionally optimize cfg80211_sme_connect() and avoid an useless schedule of conn_work.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/015b8cc5e7c4d7bb671f1984d7b7338c310b185b
- git.kernel.org/stable/c/22dfb21bf1cd876616d45cda1bc6daa89eec6747
- git.kernel.org/stable/c/2cfe78619b0de6d2da773978bc2d22797212eaa7
- git.kernel.org/stable/c/66af4a2ab1d65d556d638cb9555a3b823c2557a9
- git.kernel.org/stable/c/6f1959c17d4cb5b74af6fc31dc787e1dc3e4f6e2
- git.kernel.org/stable/c/a2a92b3e9d8e03ee3f9ee407fc46a9b4bd02d8b6
- git.kernel.org/stable/c/f4b6a138efb8a32507b8946104e32cb926308da7
- git.kernel.org/stable/c/fd081afd21eb35b968b0330700c43ec94986e1c4
Recent Use After 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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