CVE-2021-23049
On BIG-IP version 16.0.x before 16.0.1.2 and 15.1.x before 15.1.3, when the iRules RESOLVER::summarize command is used on a virtual server, undisclosed requests can cause an increase in Traffic Management Microkernel (TMM) memory utilization resulting…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.96%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
On BIG-IP version 16.0.x before 16.0.1.2 and 15.1.x before 15.1.3, when the iRules RESOLVER::summarize command is used on a virtual server, undisclosed requests can cause an increase in Traffic Management Microkernel (TMM) memory utilization resulting in an out-of-memory condition and a denial-of-service (DoS). Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.96% probability · 61th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Affected
- f5/big-ip access policy manager · f5/big-ip advanced firewall manager · f5/big-ip advanced web application firewall · f5/big-ip analytics · f5/big-ip application acceleration manager · f5/big-ip application security manager · f5/big-ip domain name system · f5/big-ip fraud protection service · f5/big-ip global traffic manager · f5/big-ip link controller · f5/big-ip local traffic manager
- Source
- f5sirt@f5.com
EPSS 1.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://support.f5.com/csp/article/K65397301Vendor Advisory
- https://support.f5.com/csp/article/K65397301Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.