Vulnerability found:
10 February 2010
Vendor informed:
10 February 2010
Severity level:
Medium/High
Credits:
Jan Fry of ProCheckUp Ltd (www.procheckup.com).
Description:
ProCheckUp has found that a remote URI redirection vulnerability affects the PGP Universal Web Messenger. This issue is due to a failure of the application to properly sanitize URI-supplied data assigned to the 'retryURL' parameter.

An attacker may leverage this issue to carry out convincing phishing attacks against unsuspecting users by causing an arbitrary page to be loaded once a PGP Universal Web Messenger specially-crafted URL is visited.

Vulnerable server-side script: '/b/lnj.e?'

Unfiltered parameter: 'retryURL'
Proof of concept:
Proof of concept:

Example of specially-crafted URL:

https://target-domain.foo/b/lnj.e?retryURL=//www.procheckup.com

Consequences:

Victim users can be redirected to third-party sites for the purpose of exploiting browser vulnerabilities or performing phishing attacks.
How to fix:
The vendor has stated that this issue has now been addressed in the PGP Universal Web Messenger.
Legal:
Copyright (c) 2012 Procheckup Ltd. All rights reserved.

Permission is granted for copying and circulating this Bulletin to the Internet community for the purpose of alerting them to problems, if and only if, the Bulletin is not edited or changed in any way, is attributed to ProCheckUp, and provided such reproduction and/or distribution is performed for non-commercial purposes.

Any other use of this information is prohibited. ProCheckUp is not liable for any misuse of this information by any third party.