Description
The TLS protocol, as well as SSL protocol 3.0 and potentially earlier versions, as implemented in various products including Microsoft Internet Information Services (IIS) 7.0, Apache HTTP Server's mod_ssl up to version 2.2.14, OpenSSL prior to 0.9.8l, GnuTLS up to 2.8.5, Mozilla's Network Security Services (NSS) up to 3.12.4, several Cisco products, and others, have a flaw in handling renegotiation handshakes. This issue fails to correctly link renegotiation handshakes with the existing connection. As a result, it allows man-in-the-middle attackers to inject unauthenticated data into HTTPS sessions, and potentially into other types of sessions secured by TLS or SSL. This vulnerability enables the processing of unauthenticated requests by the server in a context after renegotiation, leading to a "plaintext injection" attack, also known as the "Project Mogul" issue.
Remediation
- Update Software: Upgrade to the latest versions of SSL/TLS libraries (like OpenSSL) and other affected software to ensure they include security patches for this vulnerability.
- Disable Renegotiation: Temporarily disable SSL/TLS renegotiation in your server configuration if you cannot update immediately.
- Use Strong Cipher Suites: Ensure your server is configured with strong and secure cipher suites.
- Implement Security Best Practices: Regularly update systems, monitor for suspicious activities, and follow SSL/TLS configuration best practices.