Impact

As old password can be set as new password , it is considered as password policy violation.

Pimcore is not enforcing strict password policy which allow attacker to set old password as new password

Proof of Concept

1. Go to Admin link
2. login and click on -> "User | My Profile".
3. Go to change password now put old password as new password and click save.

Patches

https://github.com/pimcore/admin-ui-classic-bundle/commit/498ac77e54541177be27b0c710e387c47b3836ea.patch

Workarounds

Update to version 1.2.0 or apply this patches manually
https://github.com/pimcore/admin-ui-classic-bundle/commit/498ac77e54541177be27b0c710e387c47b3836ea.patch

References

https://huntr.com/bounties/b031199d-192a-46e5-8c02-f7284ad74021/