SIP digest authentication relay attack

Document Type Expired Internet-Draft (individual)
Authors Humberto Abdelnur  , Victor Pascual 
Last updated 2009-03-02
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


The Session Initiation Protocol (SIP [RFC3261]) provides a mechanism for creating, modifying, and terminating sessions with one or more participants. This document describes a vulnerability of SIP combined with HTTP Digest Access Authentication [RFC2617] through which an attacker can leverage the victim's credentials to send authenticated requests on his behalf. This attack is different from the man-in-the-middle (MITM) attack and does not require any eavesdropping, DNS or IP spoofing.


Humberto Abdelnur (
Victor Pascual (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)