Linux: Use After Free
CVE-2023-53307 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 71da2a151ed1adb0aea4252b16d81b53012e7afd, e3cbb4d60764295992c95344f2d779439e8b34ce, 9787b328c42c13c4f31e7d5042c4e877e9344068 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 0.17% 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 71da2a151ed1adb0aea4252b16d81b53012e7afd or e3cbb4d60764295992c95344f2d779439e8b34ce or 9787b328c42c13c4f31e7d5042c4e877e9344068 or ae16346078b1189aee934afd872d9f3d0a682c33, 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 | 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, 71da2a151ed1adb0aea4252b16d81b53012e7afd; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, e3cbb4d60764295992c95344f2d779439e8b34ce; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, 9787b328c42c13c4f31e7d5042c4e877e9344068; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, ae16346078b1189aee934afd872d9f3d0a682c33; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, a73783e4e0c4d1507794da211eeca75498544dff; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, faa7b683e436664fff5648426950718277831348; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, cc8c0dd2984503ed09efa37bcafcef3d3da104e8; 1643dfa4c2c827d6e2aa419df8c17b0f24090278 up to, but not including, f7c4d9b133c7a04ca619355574e96b6abf209fba; and 1 more ranges | 71da2a151ed1adb0aea4252b16d81b53012e7afd, e3cbb4d60764295992c95344f2d779439e8b34ce, 9787b328c42c13c4f31e7d5042c4e877e9344068, ae16346078b1189aee934afd872d9f3d0a682c33, a73783e4e0c4d1507794da211eeca75498544dff, faa7b683e436664fff5648426950718277831348 |
| Linux | Linux Kernel | 4.9 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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| 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: rbd: avoid use-after-free in do_rbd_add() when rbd_dev_create() fails If getting an ID or setting up a work queue in rbd_dev_create() fails, use-after-free on rbd_dev->rbd_client, rbd_dev->spec and rbd_dev->opts is triggered in do_rbd_add(). The root cause is that the ownership of these structures is transfered to rbd_dev prematurely and they all end up getting freed when rbd_dev_create() calls rbd_dev_free() prior to returning to do_rbd_add(). Found by Linux Verification Center (linuxtesting.org) with SVACE, an incomplete patch submitted by Natalia Petrova <[email protected]>.
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
- git.kernel.org/stable/c/71da2a151ed1adb0aea4252b16d81b53012e7afd
- git.kernel.org/stable/c/9787b328c42c13c4f31e7d5042c4e877e9344068
- git.kernel.org/stable/c/a73783e4e0c4d1507794da211eeca75498544dff
- git.kernel.org/stable/c/ae16346078b1189aee934afd872d9f3d0a682c33
- git.kernel.org/stable/c/cc8c0dd2984503ed09efa37bcafcef3d3da104e8
- git.kernel.org/stable/c/e3cbb4d60764295992c95344f2d779439e8b34ce
- git.kernel.org/stable/c/f7c4d9b133c7a04ca619355574e96b6abf209fba
- git.kernel.org/stable/c/faa7b683e436664fff5648426950718277831348
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
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