5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1 Low
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:L/AC:L/Au:N/C:P/I:N/A:N
0.0004 Low
EPSS
Percentile
5.3%
A memory leak flaw was found in the Linux kernel’s BPF subsystem in the way a user triggers the check_alu_op function of the BPF verifier. This flaw allows a local user to obtain unauthorized memory access or potentially crash the system.
The default Red Hat Enterprise Linux kernel prevents unprivileged users from being able to use eBPF by the kernel.unprivileged_bpf_disabled sysctl. This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space.
For the Red Hat Enterprise Linux 7, the eBPF for unprivileged users is always disabled.
For the Red Hat Enterprise Linux 8 to confirm the current state, inspect the sysctl with the command:
The setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw.
bugzilla.redhat.com/show_bug.cgi?id=2054865
git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=3cf2b61eb06765e27fec6799292d9fb46d0b7e60
git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b1a7288dedc6caf9023f2676b4f5ed34cf0d4029
git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=e572ff80f05c33cd0cb4860f864f5c9c044280b6
nvd.nist.gov/vuln/detail/CVE-2021-45402
www.cve.org/CVERecord?id=CVE-2021-45402
5.5 Medium
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1 Low
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:L/AC:L/Au:N/C:P/I:N/A:N
0.0004 Low
EPSS
Percentile
5.3%