CVE-2020-5929: 
F5 BIG-IP Advanced Firewall Manager vulnerability analysis and mitigation

CVE-2020-5929 affects BIG-IP platforms with specific configurations in versions 13.0.0-13.0.0 HF2, 12.1.0-12.1.2 HF1, and 11.6.1-11.6.2. The vulnerability is present in systems with Cavium Nitrox SSL hardware acceleration cards and Virtual Servers configured with Client SSL profiles using Anonymous (ADH) or Ephemeral (DHE) Diffie-Hellman key exchange without Single DH use option enabled (CVE MITRE).

The vulnerability involves crafted SSL/TLS Handshakes that may result in a Pre-Master Secret (PMS) starting with a 0 byte. This condition can lead to a recovery of plaintext messages as BIG-IP TLS/SSL ADH/DHE sends different error messages acting as an oracle. The vulnerability can also be exposed through similar error messages when PMS starts with 0 byte coupled with very precise timing measurement observation (CVE MITRE).

When successfully exploited, this vulnerability could allow attackers to recover plaintext messages from encrypted communications, potentially compromising the confidentiality of sensitive data transmitted through affected BIG-IP systems (CVE MITRE).

The vulnerability can be exploited through crafted SSL/TLS handshakes specifically targeting systems with the affected configuration. The attack requires the ability to perform precise timing measurements and analyze error messages returned by the system (CVE MITRE).

F5 has provided information about this vulnerability in their security advisory. System administrators should review their BIG-IP configurations and ensure they are running supported versions with the latest security patches (F5 Advisory).