Published:2009/09/17  Last Updated:2009/09/17

Third-party cookie issue in Opera


Opera contains an issue in which third-party cookies are not handled properly.

Products Affected

  • Opera 9.64 and earlier


Opera contains an issue in which third-party cookies are not handled properly. Please note that this issue only occurs when the user changes the setting for "Accept only cookies from the site I visit" from the default installation of Opera.


A remote attacker may be able to trace an user's activity on the web.


Update the software
Update to the latest version according to the information provided by the developer.

Vendor Status

Vendor Link
Opera Opera 10


JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2009.09.17

Measures Conditions Severity
Access Required Routed - can be attacked over the Internet using packets
  • High
Authentication None - anonymous or no authentication (IP addresses do not count)
  • High
User Interaction Required Complex - the user must be convinced to take a difficult or suspicious action. If the honest user must have elevated privileges, they are likely to be more suspicious
  • Low
Exploit Complexity Low - little to no expertise and/or luck required to exploit (cross-site scripting)
  • High

Description of each analysis measures


Hideki Sakamoto of Tsukuba Secure Network Research Co. Ltd. reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
JVN iPedia JVNDB-2009-000061

Update History