Tuleap does not sanitize properly user inputs when constructing a SQL query in the survey service.
Impact
An attacker could execute arbitrary SQL queries.
CVSSv2 score: 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P)
Exploitation
With just an user logged in, the page <tuleap_url>/survey/rating_resp.php is exploitable via the parameters vote_on_id, response and flag.
If you have an user who can administrate the survey service you can also exploit this vulnerability with the page <tuleap_url>/survey/admin/edit_survey.php and the parameter survey_id.
References
https://cwe.mitre.org/data/definitions/89.html
https://www.owasp.org/index.php/SQL_Injection