Authentication Circumvention Vulnerability in BlueFace Falcon Web Server

Reported February 13, 2002, bySNS Research.

VERSION AFFECTED

DESCRIPTION

An authentication circumvention vulnerability exists inBlueFace’s Falcon Web Server for Windows. A problem in the parsing of requestsmade to protected directories can let an attacker circumvent the Web server’sauthentication scheme and access any file in a protected directory withoutsupplying proper credentials. By supplying an additional backslash at thebeginning of the virtual path, an intruder can bypass authentication. Forexample, an attacker can bypass authentication of the "http://localhost/test"protected directory by accessing “http://localhost//test.”

VENDOR RESPONSE

Thevendor, BlueFace, has been notified andwill release build 2.0.0.1021 to correct this problem.

CREDIT
Discovered by SNSResearch.