Bugzilla is a bugtracker and testing tool developed by the Mozilla project. It is written in Perl, uses MySQL and is licensed under Mozilla Public License.
You can use Bugzilla to track issues and bugs. Moreover, it is an open source tool and is free of cost. You can remove the bug or correct it by submitting a patch for review by mentors. It supports a robust, stable RDBMS back end. Bugzilla has a lot of features to offer:
Bugzilla not only offers a simple beginner-friendly bug search, that searches the full text of a bug but also, an advanced search, wherein the user can create any search he/she wants. The user can also have time-based searches and some specific queries, like the bug status.
The users have complete control over the notifications and emails sent by Bugzilla. You get an email about any change in Bugzilla and can enable\disable any notification that you get on a particular bug.
When filing a bug in Bugzilla, as soon as you start typing a short summary for bug, it will automatically look for similar bugs in the system and allow the user to add themselves to the CC list of one of those bugs instead of filing a new one.
You can also send Bugzilla an email that will create a new bug, or will modify an existing bug and attach files to bugs.
You can estimate how many hours a bug will take to fix, and then keep track of the hours you spend working on it. You can also set a deadline that a bug must be complete by.
Bugzilla protects against SQL Injection,Cross-Site Scripting and avoids information leaks. In case someone tries to guess your password and impersonate you, the account will be automatically locked after a few attempts.
It makes the workflow completely customizable, you can add/edit the default list of bug statuses and resolutions. You can also add custom fields to your bug database, as per your organization's needs. You can also, define which groups of users can edit or see which bugs.
It has advanced reporting systems, to know how the bug database looks, you can create a table and use any search criteria to limit the bugs you want information on. You can move bugs, from an earlier version to the latest one or rather across installations.
Find more information at https://www.bugzilla.org/features/
Read it's documentation