Local kernel compromise via Btrfs transaction use-after-free
Published Feb 27, 2025 · Updated Aug 5, 2026
Use-after-free in Linux Btrfs transaction code allows local users to gain kernel privileges, read or modify protected data, or crash the system. join_transaction reads a transaction's aborted field after releasing fs_info->trans_lock without retaining a reference, allowing concurrent cleanup to free the object first. Exploitation requires local low-privileged access, a mounted Btrfs filesystem, and a transaction-abort race; the reported execution produced a KASAN-detected invalid read.
Summary
What happened
Use-after-free in Linux Btrfs transaction code allows local users to gain kernel privileges, read or modify protected data, or crash the system. join_transaction reads a transaction's aborted field after releasing fs_info->trans_lock without retaining a reference, allowing concurrent cleanup to free the object first. Exploitation requires local low-privileged access, a mounted Btrfs filesystem, and a transaction-abort race; the reported execution produced a KASAN-detected invalid read.
The record
- CVE
- CVE-2025-21753
- Published
- Feb 27, 2025
- Updated
- Aug 5, 2026
- Vendor
- Siemens
- Product
- SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 27, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <*
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo