Previous to @2ca5bb1c2f11537be8f94ca6867d8d69789e744a (release 0.1.2), tokens weren't checked for validity/expiration.

This potentially caused a security issue if expired tokens were not deleted after the expiration time was past, allowing anyone to still use invalidated authentication credentials.

References

• zf-fr/zfr-oauth2-server-module#6
• zf-fr/zfr-oauth2-server-module@2ca5bb1
• https://github.com/FriendsOfPHP/security-advisories/blob/master/zfr/zfr-oauth2-server-module/2014-04-26.yaml
• https://github.com/zf-fr/zfr-oauth2-server-module/tree/0.1.2