An issue was discovered in MantisBT through 1.3.14, and 2.0.0. Using a crafted request on bug_report_page.php (modifying the 'm_id' parameter), any user with REPORTER access or above is able to view any private issue's details (summary, description, steps to reproduce, additional information) when cloning it. By checking the 'Copy issue notes' and 'Copy attachments' checkboxes and completing the clone operation, this data also becomes public (except private notes).

MantisBT before 1.3.11, 2.x before 2.3.3, and 2.4.x before 2.4.1 omits a backslash check in string_api.php and consequently has conflicting interpretations of an initial \/ substring as introducing either a local pathname or a remote hostname, which leads to (1) arbitrary Permalink Injection via CSRF attacks on a permalink_page.php?url= URI and (2) an open redirect via a login_page.php?return= URI.

A cross-site scripting (XSS) vulnerability in the MantisBT Move Attachments page (move_attachments_page.php, part of admin tools) allows remote attackers to inject arbitrary code through a crafted 'type' parameter, if Content Security Protection (CSP) settings allows it. This is fixed in 1.3.9, 2.1.3, and 2.2.3. Note that this vulnerability is not exploitable if the admin tools directory is removed, as recommended in the "Post-installation and upgrade tasks" of the MantisBT Admin Guide. A reminder to do so is also displayed on the login page.

A cross-site scripting (XSS) vulnerability in the MantisBT Configuration Report page (adm_config_report.php) allows remote attackers to inject arbitrary code (if CSP settings permit it) through a crafted 'config_option' parameter. This is fixed in 1.3.9, 2.1.3, and 2.2.3.

A cross-site scripting (XSS) vulnerability in the MantisBT Configuration Report page (adm_config_report.php) allows remote attackers to inject arbitrary code through a crafted 'action' parameter. This is fixed in 1.3.8, 2.1.2, and 2.2.2.

MantisBT before 1.3.1 and 2.x before 2.0.0-beta.2 uses a weak Content Security Policy when using the Gravatar plugin, which allows remote attackers to conduct cross-site scripting (XSS) attacks via unspecified vectors.

Cross-site scripting (XSS) vulnerability in MantisBT Filter API in MantisBT versions before 1.2.19, and versions 2.0.0-beta1, 1.3.0-beta1 allows remote attackers to inject arbitrary web script or HTML via the 'view_type' parameter.