CVE-2021-22986

F5 BIG-IP and BIG-IQ Centralized Management contain a remote code execution vulnerability (CWE-863, improper authorization check) in the iControl REST interface. An unauthenticated attacker with network access to the REST endpoint can send crafted requests to execute arbitrary system commands, create or delete files, and disable services on the appliance or virtual instance. Successful exploitation effectively gives the attacker command-level control of the underlying F5 system, which is sufficient for account creation, persistence, lateral movement, and ransomware staging. Any organization running affected BIG-IP or BIG-IQ releases is exposed, particularly where the management interface or iControl REST is reachable from untrusted networks. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2021-11-03 with known ransomware use, EPSS places the 30-day exploitation probability at 99.9% (top percentile), though no public PoC is cataloged.

What to do: Upgrade BIG-IP and BIG-IQ to the fixed releases identified in F5's advisory (K03051234) on an urgent basis, since exploitation is in the wild and ransomware actors use this flaw. Until patched, restrict network access to the management interface and iControl REST to trusted administration networks. Because ransomware use is known, review affected devices for indicators of compromise such as unexpected commands, created or deleted files, and disabled services.