Lack of Neutralization of Formula Elements in the CSV API of MantisBT before 2.25.3 allows an unprivileged attacker to execute code or gain access to information when a user opens the csv_export.php generated CSV file in Excel.
https://www.mantisbt.org/bugs/view.php?id=29130
https://github.com/mantisbt/mantisbt/commit/7f4534c723e3162b8784aebda4836324041dbc3e