FREAK (CVE-2015-0204)

FREAK, or Factoring RSA Export Keys, is associated with CVE-2015-0204. The flaw involved support for legacy export-grade RSA cipher suites in TLS implementations.

Attack conditions

Researchers showed that a network attacker could exploit vulnerable client and server behavior to negotiate an export-grade RSA connection. A sufficiently weak temporary RSA key could then be factored, allowing the protected traffic to be compromised.

The issue was publicized in March 2015 by researchers studying TLS state-machine behavior. Their work connected FREAK to long-lived implementation support for export-era cryptographic options.

Remediation

Vendors removed or disabled export cipher suites and issued updates for affected products. The episode reinforced the principle that obsolete cryptographic compatibility modes must be removed, not merely left unused by default.

Timeline

• 2015-03FREAK is publicly disclosed.
• 2015-05A research paper on TLS composite state machines documents FREAK among the vulnerabilities found.