PT-2025-6936 · Linux+7 · Linux Kernel+7
Lion Ackermann
·
Published
2025-01-15
·
Updated
2026-01-14
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CVE-2025-21700
CVSS v3.1
7.8
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions:
Linux Kernel (affected versions not specified)
Description:
A vulnerability in the Linux kernel has been resolved, which allowed for the replacement of a child qdisc from one parent to another. This issue was discovered by Lion Ackermann, who was able to create a Use-After-Free (UAF) condition that could be abused for privilege escalation. The vulnerability is related to the
tc qdisc replace command, which can lead to a situation where a qdisc is replaced with another one, causing a UAF condition. The patch takes a preventive approach by disallowing such configuration.Technical details about exploitation include:
- API Endpoints:
/dev/lois used as the device for thetc qdiscandtc classcommands. - Vulnerable Parameters or Variables:
handle,parent,classid, andpriorityare used in thetc qdiscandtc classcommands. - Function Names:
tc qdisc add,tc qdisc replace,tc class add, andtc class deleteare used to manipulate the qdisc and class configurations.
Recommendations:
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
LPE
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Astra Linux
Debian
Linux Kernel
Linuxmint
Red Os
Suse
Ubuntu