Linux: Use After Free
CVE-2023-52752 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 2abdf136784b7edaec7ffe0f4b461b63f9c4c4de, 336a066990bb3962c46daf574ace596bda9303ce, 558817597d5fbd7af31f891b67b0fd20f0d047b7 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 0.25% 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 2abdf136784b7edaec7ffe0f4b461b63f9c4c4de or 336a066990bb3962c46daf574ace596bda9303ce or 558817597d5fbd7af31f891b67b0fd20f0d047b7 or 89929ea46f9cc11ba66d2c64713aa5d5dc723b09, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 2abdf136784b7edaec7ffe0f4b461b63f9c4c4de; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 336a066990bb3962c46daf574ace596bda9303ce; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 558817597d5fbd7af31f891b67b0fd20f0d047b7; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 89929ea46f9cc11ba66d2c64713aa5d5dc723b09; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 0ab6f842452ce2cae04209d4671ac6289d0aef8a; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, d328c09ee9f15ee5a26431f5aad7c9239fa85e62; a67172a013953664b1dad03c648200c70b90506c; 3.12.48 up to, but not including, 3.13; and 1 more ranges | 2abdf136784b7edaec7ffe0f4b461b63f9c4c4de, 336a066990bb3962c46daf574ace596bda9303ce, 558817597d5fbd7af31f891b67b0fd20f0d047b7, 89929ea46f9cc11ba66d2c64713aa5d5dc723b09, 0ab6f842452ce2cae04209d4671ac6289d0aef8a, d328c09ee9f15ee5a26431f5aad7c9239fa85e62 |
| Linux | linux_kernel | 1da177e4c3f4 | Not stated |
| Debian | Debian Linux | 11.0 | Not stated |
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: smb: client: fix use-after-free bug in cifs_debug_data_proc_show() Skip SMB sessions that are being teared down (e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show() to avoid use-after-free in @ses. This fixes the following GPF when reading from /proc/fs/cifs/DebugData while mounting and umounting [ 816.251274] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI ... [ 816.260138] Call Trace: [ 816.260329] <TASK> [ 816.260499] ? die_addr+0x36/0x90 [ 816.260762] ? exc_general_protection+0x1b3/0x410 [ 816.261126] ? asm_exc_general_protection+0x26/0x30 [ 816.261502] ? cifs_debug_tcon+0xbd/0x240 [cifs] [ 816.261878] ? cifs_debug_tcon+0xab/0x240 [cifs] [ 816.262249] cifs_debug_data_proc_show+0x516/0xdb0 [cifs] [ 816.262689] ? seq_read_iter+0x379/0x470 [ 816.262995] seq_read_iter+0x118/0x470 [ 816.263291] proc_reg_read_iter+0x53/0x90 [ 816.263596] ? srso_alias_return_thunk+0x5/0x7f [ 816.263945] vfs_read+0x201/0x350 [ 816.264211] ksys_read+0x75/0x100 [ 816.264472] do_syscall_64+0x3f/0x90 [ 816.264750] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 816.265135] RIP: 0033:0x7fd5e669d381
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/0ab6f842452ce2cae04209d4671ac6289d0aef8a
- git.kernel.org/stable/c/2abdf136784b7edaec7ffe0f4b461b63f9c4c4de
- git.kernel.org/stable/c/336a066990bb3962c46daf574ace596bda9303ce
- git.kernel.org/stable/c/558817597d5fbd7af31f891b67b0fd20f0d047b7
- git.kernel.org/stable/c/89929ea46f9cc11ba66d2c64713aa5d5dc723b09
- git.kernel.org/stable/c/d328c09ee9f15ee5a26431f5aad7c9239fa85e62
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/05/msg00030.htmlMailing List, Third Party Advisory
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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