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redhatcveRedhat.comRH:CVE-2018-25020
HistoryDec 10, 2021 - 6:24 p.m.

CVE-2018-25020

2021-12-1018:24:41
redhat.com
access.redhat.com
32

0.0004 Low

EPSS

Percentile

12.7%

A buffer overflow flaw in the Linux kernel BPF subsystem was found in the way users run BPF with long jump over an instruction sequence where inner instructions require substantial expansions into multiple BPF instructions. A local user could use this flaw to crash the system or escalate their privileges on the system.

Mitigation

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:

cat /proc/sys/kernel/unprivileged_bpf_disabled

The setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw.