This indicates an attack attempt against an Authentication Bypass vulnerability in Google Chrome web browser.
The vulnerability is due to a lack of input validation when handling HTTP Basic Authentication requests. A remote attacker can exploit this to gain unauthorized access to sensitive information.
Windows 7 & Mac OSX Mountain Lion
Google Chrome 24.0.1312.57
Security Bypass: Remote attackers can bypass security checks of vulnerable systems.
Currently we are unaware of any vendor supplied patch for this issue.