source: http://www.securityfocus.com/bid/9847/info

Multiple vulnerabilities have been identified in the application that may allow a remote attacker to carry out directory traversal and cross-site scripting attacks. A successful cross-site scripting attack may make it possible for an attacker to create a malicious link to a vulnerable site that includes hostile HTML and script code. This code may be rendered in the browser of a victim user who visits the malicious link and this will occur in the security context of the site hosting the software. The directory traversal vulnerability may allow a malicious user to request files outside of the web-server root directory with directory traversal strings such as '../'.

Pegasi Web Server version 0.2.2 has been reported to be prone to these issues, however, it is possible that other versions are affected as well.

http://www.example.com/../../../../etc/passwd
http://www.example.com/../