XScreenSaver in Sun Solaris 10 and OpenSolaris before snv_109, and Solaris 8 and 9 with GNOME 2.0 or 2.0.2, allows physically proximate attackers to obtain sensitive information by reading popup windows, which are displayed even when the screen is locked, as demonstrated by Thunderbird new-mail notifications.
http://www.vupen.com/english/advisories/2009/0978
http://www.securityfocus.com/bid/34421
http://sunsolve.sun.com/search/document.do?assetkey=1-66-255308-1
http://sunsolve.sun.com/search/document.do?assetkey=1-21-120094-22-1