Redhat.comRH:CVE-2023-23454CVE-2023-23454
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
0.0004 Low
EPSS
Percentile
14.4%
An out-of-bounds (OOB) read problem was found in cbq_classify in net/sched/sch_cbq.c in the Linux kernel. This issue may allow a local attacker to cause a denial of service due to type confusion. Non-negative numbers could indicate a TC_ACT_SHOT condition rather than valid classification results.
Mitigation
The mitigation is to disable unprivileged user namespaces by setting user.max_user_namespaces to 0:
# echo "user.max_user_namespaces=0" > /etc/sysctl.d/userns.conf
# sysctl -p /etc/sysctl.d/userns.conf
It is also possible to prevent the affected code from being loaded by blacklisting the cbq kernel module. For instructions on how to blacklist a kernel module, please see <https://access.redhat.com/solutions/41278>.
Related
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
0.0004 Low
EPSS
Percentile
14.4%