Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
CVE-2020-1959
Summary
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.
- LOW
- NETWORK
- HIGH
- UNCHANGED
- NONE
- NONE
- HIGH
- HIGH
CWE-917 - Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
The software constructs all or part of an expression language (EL) statement in a framework such as a Java Server Page (JSP) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended EL statement before it is executed.
References
Advisory Timeline
- Published
