Description

Security researchers have identified CVE-2025-20029, a command injection vulnerability in F5’s BIG-IP Traffic Management Shell (TMSH) that allows low-privileged authenticated users to execute arbitrary commands and escalate to root-level access. The flaw originates from improper input validation within the TMSH parser, enabling attackers to bypass command-line security restrictions and inject system-level commands. A proof-of-concept (PoC) exploit demonstrating remote code execution (RCE) was made public on February 24, 2025, raising concerns about potential mass exploitation. If successfully leveraged, this flaw could grant threat actors full control over the affected system, leading to data breaches, network manipulation, and unauthorized lateral movement across an organization’s IT infrastructure. The exploit takes advantage of a weakness in the TMSH syntax parser, allowing an attacker to inject shell metacharacters that split a legitimate system command into two parts: a valid "save" operation and a malicious payload executed via Bash. To carry out the attack, an adversary must have access to TMSH through SSH or the iControl REST API, using whitelisted binaries like bash or tcpdump to bypass restrictions. F5 has confirmed that BIG-IP versions v16.1.4.1 and earlier are vulnerable, making immediate patching critical. Due to the risk of full system compromise, administrators are urged to upgrade to BIG-IP v16.1.4.2 or later, restrict TMSH access to essential personnel, enforce multi-factor authentication (MFA), and monitor logs for suspicious activity. Although security patches have been released to mitigate this issue, unpatched systems remain highly vulnerable, especially with public exploitation techniques available. Given that F5 BIG-IP devices play a vital role in load balancing, firewall operations, and application delivery, CVE-2025-20029 poses a severe risk to enterprises and cloud environments. Organizations must prioritize updating affected devices and implement strict access controls to reduce the attack surface and prevent potential security breaches.