Dana Epp's ramblings at the Sanctuary: DoS Web Service with a Single Packet


« ACL Security Management in C# \| Main \| Microsoft Security Newsletter » December 11, 2003 DoS Web Service with a Single Packet Just saw on Bugtraq that you can send a specially crafted SOAP packet that has a modified DTD in it to a Web Service and the XML parser will cause the CPU load to remain at 100% for as long as the process keeps running. Another effect is that memory (hundreds of megabytes) could not be freed, even after the CPU came down from the high load. In some cases, the parser returns an out of memory error after some time. Nothing like a single packet to DoS your machine. sigh There is a fix for it. Microsoft has released an update to the .NET Framework that fixes this. It is documented in KnowledgeBase article 826231, but this article isn't actually online yet. Posted by SilverStr at December 11, 2003 12:11 PM \| TrackBack Comments Interesting, Yohimbe and his company does firewalling for soap packets. Wonder if this would apply to what they are doing? Posted by: Arcterex at December 11, 2003 01:20 PM There's more Web Services implementations then .NET!! Posted by: Wim at December 11, 2003 05:15 PM yes, but this bug only applies to .NET! Posted by: Scott at December 11, 2003 10:30 PM		My 5 Favorite Books Writing Secure Code Secure Programming Cookbook Security Engineering Secure Coding Principles & Practice Inside the Security Mind My 5 Favorite Papers Smashing the Stack Penetration Studies Covert Channel Analysis of Trusted Systems DoD Trusted Computer System Evaluation Criteria NSA Security Recommendation Guides Archives June 2006 May 2006 April 2006 March 2006 February 2006 January 2006 December 2005 November 2005 October 2005 September 2005 August 2005 July 2005 June 2005 May 2005 April 2005 March 2005 February 2005 January 2005 December 2004 November 2004 October 2004 September 2004 August 2004 July 2004 June 2004 May 2004 April 2004 March 2004 February 2004 January 2004 December 2003 November 2003 October 2003 September 2003 August 2003 July 2003 June 2003 May 2003 April 2003 March 2003 February 2003 January 2003 December 2002 November 2002 October 2002 September 2002 August 2002 July 2002 GeoURL

December 11, 2003

DoS Web Service with a Single Packet