updated 11:55 am EDT, Wed August 27, 2008
Internet BGP Exploit
A new security hole in the Internet Protocol is potentially the most severe ever discovered, according to a presentation by security experts Anton Kapela and Alex Pilosov. The two have revealed that the inherent nature of the Border Gateway Protocol (BGP), which is essential for optimizing and routing traffic on the Internet, allows a hacker to redirect traffic to his own servers and forward it along without interrupting connections or otherwise immediately exposing the attack. The method would allow a malicious user to either spy on unprotected traffic or alternately 'poison' the data with altered code before it reaches its destination.
The method can't easily be fought since the BGP protocol itself requires an explicit level of trust to work as written, the experts say. The currently proposed solution would rely on BBN Technologies chief security scientist Stephen Kent's recently developed Secure BGP standard, which would force each router online to sign its routing map data and let network providers determine whether or not they will accept changes made by that router. A provider could establish blacklists that cut off unknown or actively hostile routers.
When a fix could be implemented is unknown and may not be likely in the near future, as a similar approach was demonstrated as early as 1998 but hasn't been introduced due to the performance issues associated with signing traffic in real time. The absence of a full attack using existing BGP flaws has also reduced the pressure to implement any short-term fixes.
News of the possible attack follows after revelations of a Domain Name Server (DNS) exploit earlier in the year that could falsely point users intending to visit one website to a different address, opening them to web-based attacks. Most operating system and browser developers affected by the DNS hole have patched against it.