F5 Patches Four Critical Bugs in Big-IP Suite

Application services and network delivery firm F5 on Wednesday announced the release of patches for seven related vulnerabilities in BIG-IP, including four with a “critical” severity rating.

The BIG-IP software powers a wide range of products, including hardware, modularized software, and virtual appliances, which run on the TMOS architecture and provide customers with modules that support load balancing, firewall, access control, threat protection, and more.

On March 10, F5 announced the release of fixes for multiple vulnerabilities in BIG-IP, some of which also impact BIG-IQ, a framework designed to help with the management of BIG-IP devices and application services.

Four critical vulnerabilities in BIG-IP were announced, including one impacting BIG-IQ, along with seven high severity vulnerabilities and ten medium severity. However, the critical flaws are related to two high risk and one medium bug only.

[SEE: BIG-IP Vulnerability Exploited to Deliver DDoS Malware ]

“The bottom line is that they affect all BIG-IP and BIG-IQ customers and instances—we urge all customers to update their BIG-IP and BIG-IQ deployments to the fixed versions as soon as possible,” F5 says.

The most important of the four critical bugs is CVE-2021-22986 (CVSS score of 9.8), an unauthenticated remote command execution vulnerability in the iControl REST interface, which impacts both BIG-IP and BIG-IQ, F5 says.

An unauthenticated attacker that has network access to the iControl REST could execute arbitrary system commands, manipulate files, or disable services. Exploitation is only possible through the control plane and could lead to complete system compromise, F5 explains.

Tracked as CVE-2021-22987 (CVSS score of 9.9), the second critical bug affects the Traffic Management User Interface (TMUI) — which is also known as the Configuration utility — when running in Appliance mode, and could be abused by an authenticated remote attacker for command execution and complete system compromise.  

Two high severity — CVE-2021-22988 (CVSS score: 8.8) and CVE-2021-22989 (CVSS score: 8.0) — and one medium risk — CVE-2021-22990 (CVSS score: 6.6) — authenticated remote command execution flaws were also addressed in the TMUI.

[ALSO SEE: Vulnerability Exposes F5 BIG-IP Systems to Remote DoS Attacks ]

Tracked as CVE-2021-22991 and featuring a CVSS score of 9.0, the third critical vulnerability patched today resides in the incorrect handling of undisclosed requests to a virtual server, which could trigger a buffer overflow, leading to denial of service, or even bypass of URL-based access control and even remote code execution (RCE).

Also featuring a CVSS score of 9.0, the fourth critical bug is CVE-2021-22992, a buffer overflow that could be triggered through malicious HTTP responses to an Advanced WAF/BIG-IP ASM virtual server. Exploitation could lead to denial of service or remote code execution, thus resulting in complete system compromise, F5 explains.

F5 also announced 14 unrelated CVEs (five high severity and nine medium risk), but did not share details on them alongside the aforementioned seven vulnerabilities.

“We strongly recommend that all customers update their BIG-IP and BIG-IQ deployments to a fixed version as soon as possible—this is the only way to fully address the vulnerabilities,” F5 added.