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Case File

CVE-2021-22991

CRITICAL · CVSS 9.8 EPSS 61.06% CISA KEV · Actively Exploited Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-03-31 · Last synced 2026-08-04

CyberRota Analysis

This is a critical severity vulnerability with a CVSS score of 9.8. It affects BIG-IP. It is listed in CISA's Known Exploited Vulnerabilities catalog, indicating confirmed active exploitation in the wild. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 61.1% probability of exploitation in the next 30 days. It may be remotely exploitable.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution

Note: these links are listed for security research and verification purposes only.

CISA KEV Details

Status: This CVE is listed in CISA's Known Exploited Vulnerabilities catalog.

Ransomware use: Unknown

Added to KEV: 2022-01-18

Required action: Apply updates per vendor instructions.

CVE
CVE-2021-22991
Severity
CRITICAL
CVSS
9.8
EPSS
61.06%
BIG-IP

Original NVD Description

On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3, undisclosed requests to a virtual server may be incorrectly handled by the Traffic Management Microkernel (TMM) URI normalization, which may trigger a buffer overflow, resulting in a DoS attack. In certain situations, it may theoretically allow bypass of URL based access control or remote code execution (RCE). Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

Related CVEs

Other vulnerabilities affecting the same vendor(s)