Microsoft IIS 4.0, circa March 2000, contained a vulnerability that allowed an intruder to consume unlimited memory on a vulnerable server.
Older versions of IIS 4.0, circa March 2000, contained a vulnerability in the chunked-encoding transfer mechanism that permitted an intruder to allocate unlimited memory on the server. Quoting from Microsoft security bulletin MS00-018:
IIS 4.0 supports chunked encoding transfers, but does not limit the size of the buffer that can be reserved. This would allow a malicious user to request an extremely large buffer for a POST or PUT operation, but never actually send data, thereby blocking memory on the server that had been allocated to the session.
Intruders can interrupt the ordinary operation of a vulnerable IIS 4.0 server, potentially preventing it from responding to legitimate requests. Additionally, an intruder may be able to degrade the overall performance of other process on the machine.
Apply a patch as described in MS00-018.
Thanks to Petteri Stenius for reporting this vulnerability.
This document was written by Shawn V Hernan based on information provided by Microsoft in MS00-018
|Date First Published:||2002-06-13|
|Date Last Updated:||2002-06-13 18:42 UTC|