Some vulnerabilities and a security issue have been reported in Citrix Access Gateway, which can be exploited by malicious people to disclose sensitive information, conduct cross-site request forgery attacks, or to compromise a user's system.

1) A security issue due to residual information left on the client device can be exploited to gain unauthorized access to a user’s active session.

This security issue is reported in Access Gateway Advanced Edition 4.5 and prior.

2) A design error in the EPA ActiveX control can be exploited to download and execute arbitrary files when a user visits a malicious website.

NOTE: Unspecified errors in other client components (Net6Helper.DLL and npCtxCAO.dll as Firefox plugin) of Access Gateway Standard and Advanced Editions have also been reported, which can be exploited to execute arbitrary code in context of the logged-in user.

These vulnerabilities are reported in Access Gateway Standard Edition 4.5.2 and prior and Access Gateway Advanced Editions version 4.5 and prior with appliance firmware 4.5.2 and prior.

3) The web-based administration console of an Access Gateway appliance allows an administrator to perform certain actions via HTTP requests without performing any validity checks to verify the request. This can be exploited to e.g. change certain configuration settings by enticing a logged-in administrator to visit a malicious web site.

This vulnerability is reported in Access Gateway model 2000 appliances with firmware version 4.5.2 and prior. Access Gateway Enterprise Edition is reportedly not affected.

A redirection issue that may facilitate phishing attacks has also been reported.

Solution
Apply hotfix and update firmware to version 4.5.5.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) Martin O’Neal, Corsaire.
2) Michael White, Symantec.
3) The vendor credits Paul Johnston.

Changelog
Further details available to Secunia VIM customers

Original Advisory
Citrix:
http://support.citrix.com/article/CTX113814
http://support.citrix.com/article/CTX113815
http://support.citrix.com/article/CTX113816
http://support.citrix.com/article/CTX113817

Symantec:
http://www.symantec.com/content/en/us/enterprise/research/SYMSA-2007-006.txt

Corsaire:
http://research.corsaire.com/advisories/c060905-001.txt

Deep Links
Links available to Secunia VIM customers