CVE-2021-22991
Exploited in the wild. In CISA KEV since 2022‑01‑18. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Listed as exploited in the wild since 2022-01-18.
US federal agencies must remediate by 2022-02-01.
Apply updates per vendor instructions.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
61% chance of exploitation activity in the next 30 days, which ranks it in the 99th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
7 events over 1912 days, from the signal feeds we watch.
- OpenVAS check added
- Patch availablerecord updated
- Added to CISA KEV
- Publishedweakness classified, att&ck mapped
Affected products
- big-ip access policy managerNetworking Infrastructure / firewall
- big-ip advanced firewall managerNetworking Infrastructure / firewall
- big-ip advanced web application firewallNetworking Infrastructure / firewall
- big-ip analyticsNetworking Infrastructure / network-management
- big-ip application acceleration managerNetworking Infrastructure / load-balancer-proxy
- big-ip application security managerNetworking Infrastructure / firewall
- big-ip ddos hybrid defenderNetworking Infrastructure / firewall
- big-ip domain name systemNetworking Infrastructure / dns-dhcp-ntp
- BIG-IP Local Traffic ManagerNetworking Infrastructure / load-balancer-proxy
- BIG-IP Application Acceleration ManagerNetworking Infrastructure / load-balancer-proxy
- BIG-IP Advanced Web Application FirewallNetworking Infrastructure / firewall
- BIG-IP Advanced Firewall ManagerSecurity Products
- BIG-IP AnalyticsNetworking Infrastructure / network-management
- BIG-IP Access Policy ManagerNetworking Infrastructure / firewall
- BIG-IP Application Security ManagerNetworking Infrastructure / firewall
- BIG-IP DDos Hybrid DefenderNetworking Infrastructure / firewall
And 13 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Scored 9.8 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
References in the record
- support.f5.com/csp/article/K56715231
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22991
- support.f5.com/csp/article/K02566623&
And 5 more references. See all after sign-in
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