CVE-2021-22991
Detail
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.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
CVSS 4.0 Severity and Vector Strings:
NVD assessment
not yet provided.
CVSS 3.x Severity and Vector Strings:
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 Severity and Vector Strings:
Vector:
(AV:N/AC:M/Au:N/C:P/I:P/A:P)
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This CVE is in CISA's Known Exploited Vulnerabilities Catalog
Reference
CISA's BOD 22-01 and Known
Exploited Vulnerabilities Catalog for further guidance and requirements.
| Vulnerability Name |
Date Added |
Due Date |
Required Action |
| F5 BIG-IP Traffic Management Microkernel Buffer Overflow |
01/18/2022 |
02/01/2022 |
Apply updates per vendor instructions. |
Change History
13 change records found show changes
CVE Modified by CISA-ADP
6/16/2026 11:38:10 PM
| Action |
Type |
Old Value |
New Value |
| Added |
SSVC |
{"timestamp":"2025-01-29T20:33:09.572716Z","id":"CVE-2021-22991","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}
|
CVE Modified by F5 Networks
6/16/2026 11:38:10 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Affected |
[{"vendor":"n/a","product":"BIG-IP","versions":[{"version":"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, 12.1.x before 12.1.5.3","status":"affected"}]}]
|
Modified Analysis by NIST
10/27/2025 1:06:52 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Reference Type |
CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22991 Types: US Government Resource
|
CVE Modified by CISA-ADP
10/21/2025 8:17:25 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Reference |
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22991
|
CVE Modified by CISA-ADP
10/21/2025 4:18:21 PM
| Action |
Type |
Old Value |
New Value |
| Removed |
Reference |
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22991
|
CVE Modified by CISA-ADP
10/21/2025 3:18:53 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Reference |
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22991
|
Modified Analysis by NIST
4/02/2025 3:09:27 PM
| Action |
Type |
Old Value |
New Value |
CVE Modified by CISA-ADP
1/29/2025 4:15:10 PM
| Action |
Type |
Old Value |
New Value |
| Added |
CVSS V3.1 |
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
|
| Added |
CWE |
CWE-119
|
CVE Modified by CVE
11/21/2024 12:51:04 AM
| Action |
Type |
Old Value |
New Value |
| Added |
Reference |
https://support.f5.com/csp/article/K56715231
|
CVE Modified by F5 Networks
5/14/2024 4:18:06 AM
| Action |
Type |
Old Value |
New Value |
CWE Remap by NIST
8/08/2023 10:21:49 AM
| Action |
Type |
Old Value |
New Value |
| Changed |
CWE |
CWE-20
|
CWE-119
|
CWE Remap by NIST
7/12/2022 1:42:04 PM
| Action |
Type |
Old Value |
New Value |
| Changed |
CWE |
CWE-120
|
CWE-20
|
Initial Analysis by NIST
4/05/2021 2:56:50 PM
| Action |
Type |
Old Value |
New Value |
| Added |
CVSS V3.1 |
NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
|
| Added |
CVSS V2 |
NIST (AV:N/AC:M/Au:N/C:P/I:P/A:P)
|
| Added |
CWE |
NIST CWE-120
|
| Added |
CPE Configuration |
Record truncated, showing 2048 of 8699 characters.
View Entire Change Record
OR
*cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* versions from (including) 12.1.0 up to (excluding) 12.1.5.3
*cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* versions from (including) 13.1.0 up to (excluding) 13.1.3.6
*cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* versions from (including) 14.1.0 up to (excluding) 14.1.4
*cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* versions from (including) 15.1.0 up to (excluding) 15.1.2.1
*cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* versions from (including) 16.0.0 up to (excluding) 16.0.1.1
*cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:* versions from (including) 12.1.0 up to (excluding) 12.1.5.3
*cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:* versions from (including) 13.1.0 up to (excluding) 13.1.3.6
*cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:* versions from (including) 14.1.0 up to (excluding) 14.1.4
*cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:* versions from (including) 15.1.0 up to (excluding) 15.1.2.1
*cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:* versions from (including) 16.0.0 up to (excluding) 16.0.1.1
*cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:* versions from (including) 12.1.0 up to (excluding) 12.1.5.3
*cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:* versions from (including) 13.1.0 up to (excluding) 13.1.3.6
*cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:* versions from (including) 14.1.0 up to (excluding) 14.1.4
*cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:* versions from (including) 15.1.0 up to (excluding) 15.1.2.1
*cpe:2.3:a:f5:big-ip_advanced_web_application_firewall:*:*:*:*:*:*:*:* versions from (including) 16.0.0 up to (excluding) 16.0.1.1
*cpe:2.3:a:f5:big-ip_analytics:*:*:*:*:*:*:*:* versions from (including) 12.1.0 up to (excluding) 12.1.5.3
|
| Changed |
Reference Type |
https://support.f5.com/csp/article/K56715231 No Types Assigned
|
https://support.f5.com/csp/article/K56715231 Vendor Advisory
|
Quick Info
CVE Dictionary Entry: CVE-2021-22991 NVD
Published Date: 03/31/2021 NVD
Last Modified: 06/16/2026
Source: F5 Networks
|
