In Apache Syncope 2.1.X releases prior to 2.1.7, when the Flowable extension is enabled, an administrator with workflow entitlements can use Shell Service Tasks to perform malicious operations, including but not limited to file read, file write, and code execution.

Vulnerability to Server-Side Template Injection on Mail templates for Apache Syncope 2.0.X releases prior to 2.0.15, 2.1.X releases prior to 2.1.6, enabling attackers to inject arbitrary JEXL expressions, leading to Remote Code Execution (RCE) was discovered.

A Server-Side Template Injection was identified in Apache Syncope prior to 2.1.6 enabling attackers to inject arbitrary Java EL expressions, leading to an unauthenticated Remote Code Execution (RCE) vulnerability. Apache Syncope uses Java Bean Validation (JSR 380) custom constraint validators. When building custom constraint violation error messages, they support different types of interpolation, including Java EL expressions. Therefore, if an attacker can inject arbitrary data in the error message template being passed, they will be able to run arbitrary Java code.

It was found that the Apache Syncope EndUser UI login page prio to 2.0.15 and 2.1.6 reflects the successMessage parameters. By this mean, a user accessing the Enduser UI could execute javascript code from URL query string.