User Enumeration in kareadita/kavita


Reported on

Oct 27th 2022


The migrate-email endpoint is requiring Email, Username, and Password parameter. The Username parameter value will be queried to _userManager.Users and will returning data to user variable, if user variable contain null value, the application will return bad request with "Invalid username" message, which is similar to user doesn't exist message.

This bad request message can be used for user enumeration, with the asumption if an Username parameter value using the valid username, the backend will returing the different message.

Proof of Concept

1. Send a request with the following parameter :

- Email parameter with any email value
- Username parameter with any value
- Password parameter with any value

2. The backend will response "Invalid username"

3. An then, try to put the valid Username on Username parameter.

4. The backend will response "Your credentials are not correct".


An attacker could perform an bruteforce attack to either guess or confirm valid users in a system.

We are processing your report and will contact the kareadita/kavita team within 24 hours. a month ago
We have contacted a member of the kareadita/kavita team and are waiting to hear back a month ago
kareadita/kavita maintainer has acknowledged this report a month ago
Joe Milazzo validated this vulnerability a month ago
zetc0de has been awarded the disclosure bounty
The fix bounty is now up for grabs
The researcher's credibility has increased: +7
Joe Milazzo marked this as fixed in with commit f8db37 a month ago
The fix bounty has been dropped
This vulnerability has been assigned a CVE
a month ago


@admin can disclose this report? Also can to assign cve for this vulnerability?

Joe Milazzo
a month ago

This is not ready for disclosure. I will publish when it is ready.

Joe Milazzo published this vulnerability 25 days ago
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