Linux: Use After Free
CVE-2022-49388 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 25ff1e3a1351c0d936dd1ac2f9e58231ea1510c9, abb67043060f2bf4c03d7c3debb9ae980e2b6db3, 8302620aeb940f386817321d272b12411ae7d39f 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 0.29% 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 25ff1e3a1351c0d936dd1ac2f9e58231ea1510c9 or abb67043060f2bf4c03d7c3debb9ae980e2b6db3 or 8302620aeb940f386817321d272b12411ae7d39f or 6d8d3f68cbecfd31925796f0fb668eb21ab06734, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.14.283 or 4.19.247 or 5.4.198 or 5.10.122, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, 25ff1e3a1351c0d936dd1ac2f9e58231ea1510c9; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, abb67043060f2bf4c03d7c3debb9ae980e2b6db3; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, 8302620aeb940f386817321d272b12411ae7d39f; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, 6d8d3f68cbecfd31925796f0fb668eb21ab06734; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, 5ff2514e4fb55dcf3d88294686040ca73ea0c1a2; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, e27ecf325e51abd06aaefba57a6322a46fa4178b; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, 1174ab8ba36a48025b68b5ff1085000b1e510217; 493cfaeaa0c9bc0c79ce5751193d49fdac9aaaec up to, but not including, 8c03a1c21d72210f81cb369cc528e3fde4b45411; and 1 more ranges | 25ff1e3a1351c0d936dd1ac2f9e58231ea1510c9, abb67043060f2bf4c03d7c3debb9ae980e2b6db3, 8302620aeb940f386817321d272b12411ae7d39f, 6d8d3f68cbecfd31925796f0fb668eb21ab06734, 5ff2514e4fb55dcf3d88294686040ca73ea0c1a2, e27ecf325e51abd06aaefba57a6322a46fa4178b |
| Linux | Linux Kernel | 4.12 up to, but not including, 4.14.283; 4.15 up to, but not including, 4.19.247; 4.20 up to, but not including, 5.4.198; 5.5 up to, but not including, 5.10.122; 5.11 up to, but not including, 5.15.47; 5.16 up to, but not including, 5.17.15; 5.18 up to, but not including, 5.18.4 | 4.14.283, 4.19.247, 5.4.198, 5.10.122, 5.15.47, 5.17.15 |
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 CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: ubi: ubi_create_volume: Fix use-after-free when volume creation failed There is an use-after-free problem for 'eba_tbl' in ubi_create_volume()'s error handling path: ubi_eba_replace_table(vol, eba_tbl) vol->eba_tbl = tbl out_mapping: ubi_eba_destroy_table(eba_tbl) // Free 'eba_tbl' out_unlock: put_device(&vol->dev) vol_release kfree(tbl->entries) // UAF Fix it by removing redundant 'eba_tbl' releasing. Fetch a reproducer in [Link].
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/1174ab8ba36a48025b68b5ff1085000b1e510217
- git.kernel.org/stable/c/25ff1e3a1351c0d936dd1ac2f9e58231ea1510c9
- git.kernel.org/stable/c/5ff2514e4fb55dcf3d88294686040ca73ea0c1a2
- git.kernel.org/stable/c/6d8d3f68cbecfd31925796f0fb668eb21ab06734
- git.kernel.org/stable/c/8302620aeb940f386817321d272b12411ae7d39f
- git.kernel.org/stable/c/8c03a1c21d72210f81cb369cc528e3fde4b45411
- git.kernel.org/stable/c/abb67043060f2bf4c03d7c3debb9ae980e2b6db3
- git.kernel.org/stable/c/e27ecf325e51abd06aaefba57a6322a46fa4178b
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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