The GeckoActiveXObject function in Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, generates different exception messages depending on whether the referenced COM object is listed in the registry, which allows remote attackers to obtain potentially sensitive information about installed software by making multiple calls that specify the ProgID values of different COM objects.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7958
https://exchange.xforce.ibmcloud.com/vulnerabilities/54798
https://bugzilla.redhat.com/show_bug.cgi?id=546729
https://bugzilla.mozilla.org/show_bug.cgi?id=503451
http://www.vupen.com/english/advisories/2009/3547
http://www.securityfocus.com/bid/37360
http://www.securityfocus.com/bid/37349
http://www.mozilla.org/security/announce/2009/mfsa2009-71.html
http://securitytracker.com/id?1023347
http://securitytracker.com/id?1023346