CVE-2020-5921
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12...
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.2, Syn flood causes large number of MCPD context messages destined to secondary blades consuming memory leading to MCPD failure. This issue affects only VIPRION hosts with two or more blades installed. Single-blade VIPRION hosts are not affected.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.2, Syn flood causes large number of MCPD context messages destined to secondary blades consuming memory leading to MCPD failure. This issue affects only VIPRION hosts with two or more blades installed. Single-blade VIPRION hosts are not affected.
- Record
CVE-2020-5921- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Updated
- 2026-11-02
CVE List No score
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.2, Syn flood causes large number of MCPD context messages destined to secondary blades consuming memory leading to MCPD failure. This issue affects only VIPRION hosts with two or more blades installed. Single-blade VIPRION hosts are not affected.
- Record
CVE-2020-5921- Updated
- 2026-11-02
EUVDEUVD-2020-27075 No score
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.2, Syn flood causes large number of MCPD context messages destined to secondary blades consuming memory leading to MCPD failure. This issue affects only VIPRION hosts with two or more blades installed. Single-blade VIPRION hosts are not affected.
- Record
EUVD-2020-27075- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3wm8-xffc-5pg9 No score
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12...
in BIG-IP versions 15.1.0-15.1.0.4, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, 13.1.0-13.1.3.4, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.2, Syn flood causes large number of MCPD context messages destined to secondary blades consuming memory leading to MCPD failure. This issue affects only VIPRION hosts with two or more blades installed. Single-blade VIPRION hosts are not affected.
- Record
GHSA-3wm8-xffc-5pg9- Weakness
- CWE-400
- Updated
- 2026-11-02
Affected products
- f5 big-ip
- f5 big-ip access policy manager
- f5 big-ip advanced firewall manager
- 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
- f5 big-ip policy enforcement manager
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-5921 is a high vulnerability (CVSS 7.5) in F5 Big-ip, published August 26, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.04%, the 64th percentile. No source names a fixed version.