I'm hosting an (ancient) joomla 3.9 version that has been running smoothly for the past 5 years.
As it's mostly static content, I haven't logged into it since at least a year.
In order to finally upgrade it to a more recent version, I first decided to log back in and I'm unable to do so.
Thing is, when I click the login button, the request gets sent and a single 303 response is sent with a followup set to the same page I was before.
And there is no message on the page telling me that I typed the wrong password or something along those lines.
I tried the /administrator or the /component/users/?Itemid=123456 pages and they exhibit the same behavior in all those cases:
- Use an existing login with correct password
- Use an existing login with knowingly incorrect password
- Use an non existing login with any password
