CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
25.6%
There are 3 CVEs for the use-after-free flaw found in net/sched/cls_fw.c in classifiers (cls_fw, cls_u32, and cls_route) in the Linux Kernel: CVE-2023-4206, CVE-2023-4207, CVE-2023-4208. A local user could use any of these flaws to crash the system or potentially escalate their privileges on the system. Similar CVE-2023-4128 was rejected as a duplicate.
To mitigate this issue, prevent the module cls_u32 from being loaded by blacklisting the module to prevent it from loading automatically.
https://access.redhat.com/solutions/41278
bugzilla.redhat.com/show_bug.cgi?id=2225511
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76e42ae831991c828cffa8c37736ebfb831ad5ec
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8
lore.kernel.org/netdev/[email protected]/
nvd.nist.gov/vuln/detail/CVE-2023-4208
www.cve.org/CVERecord?id=CVE-2023-4208