CVE-2021-22991
Confirmed PUBLISHEDOn 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,...
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Mar 31, 2021
- Exploitation Reported
- Jan 18, 2022
- CVSS
- 9.8 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n/a |
BIG-IP
|
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 |
Affected |
CVE References
- support.f5.com/csp/article/K56715231 support.f5.com · CVE Record https://support.f5.com/csp/article/K56715231
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2022-01-18 00:00 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:N/AC:M/Au:N/C:P/I:P/A:P
Exploitation Status
Exploited in the wild
Recorded 2022-01-18 00:00:00 UTC · CISA
Weaknesses (CWE)
-
Improper Restriction of Operations within the Bounds of a Memory Buffer
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
17:23 UTC over 5 years ago17:23 UTC · over 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-22991
{
"cve_id": "CVE-2021-22991",
"title": "On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x bef...",
"affected_vendor": "F5",
"affected_product": "BIG-IP",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 9.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}