In F5 BIG-IP LTM, AAM, AFM, Analytics, APM, ASM, DNS, GTM, Link Controller, PEM and Websafe software version 12.0.0 to 12.1.1, 11.6.0 to 11.6.1, 11.5.0 - 11.5.4, virtual servers with a configuration using the HTTP Explicit Proxy functionality and/or SOCKS profile are vulnerable to an unauthenticated, remote attack that allows modification of BIG-IP system configuration, extraction of sensitive system files, and/or possible remote command execution on the BIG-IP system.
https://support.f5.com/csp/article/K02692210