⚠ Actively exploited
Added to CISA KEV on 2022-01-18. Federal agencies required to patch by 2022-02-01. Required action: Apply updates per vendor instructions..

CVE-2021-22991

CWE-119 — Buffer OverflowCWE-120 — Classic Buffer OverflowCWE-20 — Improper Input Validation7 documents7 sources
Severity
9.8CRITICAL
EPSS
73.1%
top 1.21%
CISA KEV
KEV
Added 2022-01-18
Due 2022-02-01
Exploit
Exploited in wild
Active exploitation observed
Affected products
14
F5 Big-ip Access Policy ManagerF5 Big-ip Advanced Firewall ManagerF5 Big-ip Advanced WEB Application Firewall+11 more
Timeline
PublishedMar 31
KEV addedJan 18
KEV dueFeb 1
Latest updateMay 24
CISA Required Action: Apply updates per vendor instructions.

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 …

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages15 packages

▶NVDf5/big-ip_link_controller12.1.0 — 12.1.5.3+4
▶NVDf5/big-ip_access_policy_manager12.1.0 — 12.1.5.3+4
▶NVDf5/big-ip_local_traffic_manager12.1.0 — 12.1.5.3+4
▶NVDf5/big-ip_global_traffic_manager12.1.0 — 12.1.5.3+4
▶NVDf5/big-ip_analytics12.1.0 — 12.1.5.3+4

🔴Vulnerability Details

3
GHSA
GHSA-6w8r-pjm3-q7x7: On BIG-IP versions 16↗2022-05-24
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CVEList
CVE-2021-22991: On BIG-IP versions 16↗2021-03-31
▶
VulnCheck
F5 BIG-IP Traffic Management Microkernel Buffer Overflow↗2021
▶

🔍Detection Rules

1
Suricata
ET EXPLOIT Possible F5 BIG-IP Infoleak and Out-of-Bounds Write Inbound (CVE-2021-22991)↗2021-03-18
▶

📋Vendor Advisories

2
CISA
F5 BIG-IP Traffic Management Microkernel Buffer Overflow↗2022-01-18
▶
F5
CVE-2021-22991: On BIG-IP versions 16↗2021-03-31
▶
CVE-2021-22991 (CRITICAL CVSS 9.8) | On BIG-IP versions 16.0.x before 16 | cvebase.io