An issue was discovered in Mahara before 15.04.14, 16.x before 16.04.8, 16.10.x before 16.10.5, and 17.x before 17.04.3. When one closes the browser without logging out of Mahara, the value in the usr_session table is not removed. If someone were to open a browser, visit the Mahara site, and adjust the 'mahara' cookie to the old value, they can get access to the user's account.
Mahara 1.9 before 1.9.8 and 1.10 before 1.10.6 and 15.04 before 15.04.3 are vulnerable to perform a cross-site request forgery (CSRF) attack on the uploader contained in Mahara's filebrowser widget. This could allow an attacker to trick a Mahara user into unknowingly uploading malicious files into their Mahara account.
Mahara 17.04 before 17.04.8 and 17.10 before 17.10.5 and 18.04 before 18.04.1 can be used as medium to transmit viruses by placing infected files into a Leap2A archive and uploading that to Mahara. In contrast to other ZIP files that are uploaded, ClamAV (when activated) does not check Leap2A archives for viruses, allowing malicious files to be available for download. While files cannot be executed on Mahara itself, Mahara can be used to transfer such files to user computers.
An issue was discovered in Mahara before 18.10.0. It mishandled user requests that could discontinue a user's ability to maintain their own account (changing username, changing primary email address, deleting account). The correct behavior was to either prompt them for their password and/or send a warning to their primary email address.