Local privilege escalation via stale route filter
Published Jan 8, 2024 · Updated May 22, 2025
Use-after-free in the Linux kernel cls_route filter allows local users to crash the system or execute arbitrary code. In route4_change, replacing a handle-zero filter frees the old route4_filter without unlinking it from the hash list, leaving a stale reference that can be freed again. Triggering requires local access and user namespaces; the demonstrated DirtyCred exploit rewrites protected file credentials to obtain root privileges.
Summary
What happened
Use-after-free in the Linux kernel cls_route filter allows local users to crash the system or execute arbitrary code. In route4_change, replacing a handle-zero filter frees the old route4_filter without unlinking it from the hash list, leaving a stale reference that can be freed again. Triggering requires local access and user namespaces; the demonstrated DirtyCred exploit rewrites protected file credentials to obtain root privileges.
The record
- CVE
- CVE-2022-2588
- Published
- Jan 8, 2024
- Updated
- May 22, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 8, 2024CVE publishedPublication date reported by the CVE source.
- May 22, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.0~rc1
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.
Weakness, pattern, technique
Public exploit references
- Markakd CVE-2022-2588 DirtyCred exploitfunctional · demonstrated
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Technologies
Your stack
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Your stack
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