Vulnerability Description
A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 2.6.12, < 4.14.327 |
| Debian | Debian Linux | 10.0 |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSThird Party AdvisoryVDB Entry
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3Issue TrackingMailing ListPatch
- https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60fPatchVendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing ListThird Party Advisory
- http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSThird Party AdvisoryVDB Entry
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3Issue TrackingMailing ListPatch
- https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60fPatchVendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing ListThird Party Advisory
FAQ
What is CVE-2023-4623?
CVE-2023-4623 is a vulnerability with a CVSS score of 7.8 (HIGH). A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing ...
How severe is CVE-2023-4623?
CVE-2023-4623 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2023-4623?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Debian Debian Linux.