Privilege escalation in Linux kernel BPF subsystem

1) Buffer overflow

EUVDB-ID: #VU61205

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-25020

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 4.0 - 4.16.18

External links

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

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.