Impact
The Flarum /logout route includes a redirect parameter that allows any third party to redirect users from a (trusted) domain of the Flarum installation to redirect to any link. Sample: example.com/logout?return=https://google.com. For logged-in users, the logout must be confirmed. Guests are immediately redirected. This could be used by spammers to redirect to a web address using a trusted domain of a running Flarum installation.
Some ecosystem extensions modifying the logout route have already been affected. Sample: https://discuss.flarum.org/d/22229-premium-wordpress-integration/526
Patches
The vulnerability has been fixed and published as flarum/core v1.8.5. All communities running Flarum should upgrade as soon as possible to v1.8.5 using:
composer update --prefer-dist --no-dev -a -W
You can then confirm you run the latest version using:
composer show flarum/core
Workarounds
Some extensions modifying the logout route can remedy this issue if their implementation is safe. In any case we recommend updating to 1.8.5.
References
For any questions or comments on this vulnerability, please visit https://discuss.flarum.org/
For support questions, create a discussion at https://discuss.flarum.org/t/support.
A reminder that if you ever become aware of a security issue in Flarum, please report it to us privately by emailing security@flarum.org, and we will address it promptly.
imorland Analyst
DavideIadeluca Finder
Impact
The Flarum
/logoutroute includes a redirect parameter that allows any third party to redirect users from a (trusted) domain of the Flarum installation to redirect to any link. Sample:example.com/logout?return=https://google.com. For logged-in users, the logout must be confirmed. Guests are immediately redirected. This could be used by spammers to redirect to a web address using a trusted domain of a running Flarum installation.Some ecosystem extensions modifying the logout route have already been affected. Sample: https://discuss.flarum.org/d/22229-premium-wordpress-integration/526
Patches
The vulnerability has been fixed and published as flarum/core v1.8.5. All communities running Flarum should upgrade as soon as possible to v1.8.5 using:
composer update --prefer-dist --no-dev -a -WYou can then confirm you run the latest version using:
composer show flarum/coreWorkarounds
Some extensions modifying the logout route can remedy this issue if their implementation is safe. In any case we recommend updating to 1.8.5.
References
For any questions or comments on this vulnerability, please visit https://discuss.flarum.org/
For support questions, create a discussion at https://discuss.flarum.org/t/support.
A reminder that if you ever become aware of a security issue in Flarum, please report it to us privately by emailing security@flarum.org, and we will address it promptly.