Linux: Use After Free
CVE-2023-53075 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 2de28e5ce34b22b73b833a21e2c45ae3aade3964, 7569ee04b0e3b32df79f64db3a7138573edad9bc, ac58b88ccbbb8e9fb83e137cee04a856b1ea6635 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 0.21% 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 2de28e5ce34b22b73b833a21e2c45ae3aade3964 or 7569ee04b0e3b32df79f64db3a7138573edad9bc or ac58b88ccbbb8e9fb83e137cee04a856b1ea6635 or 83c3b2f4e7c61367c7b24551f4c6eb94bbdda283, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.14.311 or 4.19.279 or 5.4.238 or 5.10.176, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, 2de28e5ce34b22b73b833a21e2c45ae3aade3964; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, 7569ee04b0e3b32df79f64db3a7138573edad9bc; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, ac58b88ccbbb8e9fb83e137cee04a856b1ea6635; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, 83c3b2f4e7c61367c7b24551f4c6eb94bbdda283; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, 2a0d71fabfeb349216d33f001a6421b1768bd3a9; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, 4f84f31f63416b0f02fc146ffdc4ab32723eb7e8; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, f1bd8b7fd890d87d0dc4dedc6287ea34dd07c0b4; 9644302e3315e7e36495d230d5ac7125a316d33e up to, but not including, ee92fa443358f4fc0017c1d0d325c27b37802504; and 1 more ranges | 2de28e5ce34b22b73b833a21e2c45ae3aade3964, 7569ee04b0e3b32df79f64db3a7138573edad9bc, ac58b88ccbbb8e9fb83e137cee04a856b1ea6635, 83c3b2f4e7c61367c7b24551f4c6eb94bbdda283, 2a0d71fabfeb349216d33f001a6421b1768bd3a9, 4f84f31f63416b0f02fc146ffdc4ab32723eb7e8 |
| Linux | Linux Kernel | 3.5 up to, but not including, 4.14.311; 4.15 up to, but not including, 4.19.279; 4.20 up to, but not including, 5.4.238; 5.5 up to, but not including, 5.10.176; 5.11 up to, but not including, 5.15.104; 5.16 up to, but not including, 6.1.21; 6.2 up to, but not including, 6.2.8; 6.3 | 4.14.311, 4.19.279, 5.4.238, 5.10.176, 5.15.104, 6.1.21 |
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: ftrace: Fix invalid address access in lookup_rec() when index is 0 KASAN reported follow problem: BUG: KASAN: use-after-free in lookup_rec Read of size 8 at addr ffff000199270ff0 by task modprobe CPU: 2 Comm: modprobe Call trace: kasan_report __asan_load8 lookup_rec ftrace_location arch_check_ftrace_location check_kprobe_address_safe register_kprobe When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a pg which is newly added to ftrace_pages_start in ftrace_process_locs(). Before the first pg->index++, index is 0 and accessing pg->records[-1].ip will cause this problem. Don't check the ip when pg->index is 0.
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/2a0d71fabfeb349216d33f001a6421b1768bd3a9
- git.kernel.org/stable/c/2de28e5ce34b22b73b833a21e2c45ae3aade3964
- git.kernel.org/stable/c/4f84f31f63416b0f02fc146ffdc4ab32723eb7e8
- git.kernel.org/stable/c/7569ee04b0e3b32df79f64db3a7138573edad9bc
- git.kernel.org/stable/c/83c3b2f4e7c61367c7b24551f4c6eb94bbdda283
- git.kernel.org/stable/c/ac58b88ccbbb8e9fb83e137cee04a856b1ea6635
- git.kernel.org/stable/c/ee92fa443358f4fc0017c1d0d325c27b37802504
- git.kernel.org/stable/c/f1bd8b7fd890d87d0dc4dedc6287ea34dd07c0b4
Recent Use After Free vulnerabilities
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- 7.8 High severity
- 7.8 High severity
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