SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-5929

In versions 13.0.0-13.0.0 HF2, 12.1.0-12.1.2 HF1, and 11.6.1-11.6.2, BIG-IP platforms with Cavium Nitrox SSL hardware acceleration cards, a Virtual Server configured with a Client SSL profile, and using Anonymous (ADH) or Ephemeral (DHE) Diffie-Hellman…

MEDIUM 5.9EPSS 1.09%

Does this matter?

Lower severity and a low EPSS score (1.09%). Track it; it rarely justifies an emergency change on its own.

Description

In versions 13.0.0-13.0.0 HF2, 12.1.0-12.1.2 HF1, and 11.6.1-11.6.2, BIG-IP platforms with Cavium Nitrox SSL hardware acceleration cards, a Virtual Server configured with a Client SSL profile, and using Anonymous (ADH) or Ephemeral (DHE) Diffie-Hellman key exchange and Single DH use option not enabled in the options list may be vulnerable to crafted SSL/TLS Handshakes that may result with a PMS (Pre-Master Secret) that starts in a 0 byte and may lead to a recovery of plaintext messages as BIG-IP TLS/SSL ADH/DHE sends different error messages acting as an oracle. Similar error messages when PMS starts with 0 byte coupled with very precise timing measurement observation may also expose this vulnerability.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.09% probability · 65th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-203
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 ddos hybrid defender · 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 · f5/ssl orchestrator
Source
f5sirt@f5.com
EPSS trend
0%3%5%26 October 2026: 1.09%26 October 202626 October 2026

EPSS 1.1% 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.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.