Privilege escalation in F5 BIG-IP (Linux kernel component)

1) Out-of-bounds write

EUVDB-ID: #VU56017

Risk: Low

CVSSv4.0: 8.5 [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:A/U:Clear]

CVE-ID: CVE-2021-22555

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: Yes

Description

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

The vulnerability exists due to a boundary error when processing untrusted input in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

BIG-IP: 13.1.0 - 17.0.0

CPE2.3

• cpe:2.3:h:f5_networks:big-ip:13.1.5:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip:14.1.5:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip:15.1.6:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip:16.1.3:*:*:*:*:*:*:*
• cpe:2.3:h:f5_networks:big-ip:17.0.0:*:*:*:*:*:*:*

External links

http://support.f5.com/csp/article/K06524534

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. However, a fully functional exploit for this vulnerability is available.