Local privilege escalation via stale qdisc class
Published Jul 19, 2025 · Updated Aug 5, 2026
Use-after-free in Linux traffic control allows local users to execute code in the kernel through a crafted classful qdisc hierarchy. During enqueue, a classful qdisc can dequeue and empty its child, qlen_notify marks the class passive, and later reactivation dereferences the stale class pointer. An unprivileged local user can reach the rtnetlink operations inside user and network namespaces; exploitation can corrupt kernel memory or crash the system.
Summary
What happened
Use-after-free in Linux traffic control allows local users to execute code in the kernel through a crafted classful qdisc hierarchy. During enqueue, a classful qdisc can dequeue and empty its child, qlen_notify marks the class passive, and later reactivation dereferences the stale class pointer. An unprivileged local user can reach the rtnetlink operations inside user and network namespaces; exploitation can corrupt kernel memory or crash the system.
The record
- CVE
- CVE-2025-38350
- Published
- Jul 19, 2025
- Updated
- Aug 5, 2026
- Vendor
- Siemens
- Product
- SCALANCE XRM334 (24 V DC, 12xFO)
- Classifications
- CWE-20, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 19, 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 <V3.3
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
- Published classful-qdisc reproducerproof of concept · demonstrated
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