SB2021120824 - Privilege escalation in Linux kernel BPF subsystem

Description

This security bulletin contains information about 1 vulnerability.

1) Buffer overflow (CVE-ID: CVE-2018-25020)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the BPF subsystem in the Linux kernel in ernel/bpf/core.c and net/core/filter.c. The kernel mishandles situations with a long jump over an instruction sequence where inner instructions require substantial expansions into multiple BPF instructions. A local user can run a specially crafted program to trigger memory corruption and execute arbitrary code with elevated privileges.

Remediation

Install update from vendor's website.

References

• https://github.com/torvalds/linux/commit/050fad7c4534c13c8eb1d9c2ba66012e014773cb
• https://security.netapp.com/advisory/ntap-20211229-0005/
• http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html