CVE-2023-4623
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.28% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel · debian/debian linux
- Source
- cve-coordination@google.com
References
- http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.htmlThird Party Advisory, VDB Entry
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60fIssue Tracking, Mailing List, Patch, Vendor Advisory
- https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60fPatch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing List, Third Party Advisory
- http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.htmlThird Party Advisory, VDB Entry
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60fIssue Tracking, Mailing List, Patch, Vendor Advisory
- https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60fPatch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.