CVE-2020-17530: Apache Struts Remote Code Execution Vulnerability

Vulnerability summary

CVE-2020-17530 is a critical (CVSS 9.8) Expression Language Injection vulnerability in Apache Struts. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 95.93% chance of exploitation in the next 30 days, higher than 99.8% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 11-12-2020
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVApache Struts Remote Code Execution Vulnerability
3. 03-05-2022
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

Forced OGNL evaluation, when evaluated on raw user input in tag attributes, may lead to remote code execution. Affected software : Apache Struts 2.0.0 - Struts 2.5.25.

• CWE-917Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')The product 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.