Transport Layer Security Renegotiation Vulnerability

An article by Fabio Semperboni    No Comments

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Security researchers Marsh Ray and Steve Dispensa unveiled the TLS (Transport Layer Security) flaw on Wednesday, following the disclosure of separate, but similar, security findings. TLS and its predecessor, SSL (Secure Sockets Layer), are typically used by online retailers and banks to provide security for web transactions. Ray explained in a blog post on Thursday that he had initially discovered the flaw in August, and demonstrated a working exploit to Dispensa at the beginning of September.

This vulnerability could impact any Cisco product that uses any version of TLS and SSL.

Affected Products:
Cisco is currently evaluating products for possible exposure to these TLS issues. Products will only be listed in the Vulnerable Products or Products Confirmed Not Vulnerable sections of this advisory when a final determination about product exposure is made

Details:
TLS and its predecessor, SSL, are cryptographic protocols that provide security for communications over IP data networks such as the Internet. An industry-wide vulnerability exists in the TLS protocol that could impact any Cisco product that uses any version of TLS and SSL. The vulnerability exists in how the protocol handles session renegotiation and exposes users to a potential man-in-the-middle attack.

Exploitation and Public Announcements:
This vulnerability was initially discovered by Marsh Ray and Steve Dispensa from PhoneFactor, Inc.
Cisco is not aware of any malicious exploitation of this vulnerability. Proof-of-concept exploit code has been published for this vulnerability.

Link: http://www.cisco.com/…/products_security_advisory09186a0080b01d1d.shtml