CVE intelligence and bounded remediation

CVE-2020-5929 — F5 Big-Ip Access Policy Manager security vulnerability

Medium CVSS 5.9

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.

Severity
Medium
CVSS
5.9 (3.1)
Published
2020-09-25
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-203

Affected products

  • f5 / big-ip_access_policy_manager
  • f5 / big-ip_access_policy_manager / 11.6.2
  • f5 / big-ip_access_policy_manager / 12.1.2
  • f5 / big-ip_access_policy_manager / 13.0.0
  • f5 / big-ip_advanced_firewall_manager
  • f5 / big-ip_advanced_firewall_manager / 11.6.2

Showing 6 representative product identities from 112 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Information disclosure and sensitive data exposure

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace sensitive data through responses, errors, logs, metrics, traces, caches, exports, files, backups, and client bundles.
  • Identify affected subjects, tenants, retention windows, access controls, and downstream copies without opening unnecessary sensitive records.
  • Review metadata, timing, status, length, and existence signals as well as direct content disclosure.

Remediate safely

  • Minimize collection and output, apply field-level authorization and redaction at a centralized boundary, and return generic external errors.
  • Remove secrets and sensitive data from logs, artifacts, URLs, caches, and client-side bundles; rotate credentials that may have been exposed.
  • Update the affected component and add synthetic-data tests for response, error, observability, and export paths.

Authoritative sources

Complete CVE record and remediation plan

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