Debian Linux
CVE-2023-4921
HIGH
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
1DescriptionNVD
A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation.
When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue().
We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.
AnalysisAI
A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Technical ContextAI
This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8. Affected products include: Linux Linux Kernel, Debian Debian Linux.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.
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Same weakness CWE-416 – Use After Free
View allSame technique Privilege Escalation
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External POC / Exploit Code
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