Multiple SQL injection vulnerabilities in Koha 3.14.x before 3.14.16, 3.16.x before 3.16.12, 3.18.x before 3.18.08, and 3.20.x before 3.20.1 allow (1) remote attackers to execute arbitrary SQL commands via the number parameter to opac-tags_subject.pl in the OPAC interface or (2) remote authenticated users to execute arbitrary SQL commands via the Filter or (3) Criteria parameter to reports/borrowers_out.pl in the Staff interface.
The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.