CVE-2012-0391
Apache Struts 2 Improper Input Validation Vulnerability
Apache Struts 2
The ExceptionDelegator component in Apache Struts before 2.2.3.1 interprets parameter values as OGNL expressions during certain exception handling for mismatched data types of properties, which allows remote attackers to execute arbitrary Java code via a crafted parameter.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 21 January 2022. US federal agencies were required to remediate it by 21 July 2022.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 75.6%, which is higher than 99.5% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2012-0391 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2012-0391.
What does CVE-2012-0391 affect?
CVE-2012-0391 affects Apache Struts 2. The ExceptionDelegator component in Apache Struts before 2.2.3.1 interprets parameter values as OGNL expressions during certain exception handling for mismatched data types of properties, which allows remote attackers to execute arbitrary Java code via a crafted parameter.
How severe is CVE-2012-0391?
CVE-2012-0391 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 75.6%, higher than 99.5% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 21 July 2022.
How should organisations respond to CVE-2012-0391?
Apply the vendor patch for Apache Struts 2 as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.