Semmle security researcher Man Yue Mo has disclosed a critical remote code execution vulnerability in the popular Apache Struts web application framework that could allow remote attackers to run malicious code on the affected servers.
Apache Struts is an open source framework for developing web applications in the Java programming language and is widely used by enterprises globally, including by 65 percent of the Fortune 100 companies, like Vodafone, Lockheed Martin, Virgin Atlantic, and the IRS.
The vulnerability (CVE-2018-11776) resides in the core of Apache Struts and originates because of insufficient validation of user-provided untrusted inputs in the core of the Struts framework under certain configurations.
The newly found Apache Struts exploit can be triggered just by visiting a specially crafted URL on the affected web server, allowing attackers to execute malicious code and eventually take complete control over the targeted server running the vulnerable application.
Your Apache Struts implementation is vulnerable to the reported RCE flaw if it meets the following conditions:
- The alwaysSelectFullNamespace flag is set to true in the Struts configuration.
- Struts configuration file contains an “action” or “url” tag that does not specify the optional namespace attribute or specifies a wildcard namespace.
According to the researcher, even if an application is currently not vulnerable, “an inadvertent change to a Struts configuration file may render the application vulnerable in the future.”
Read more: The Hacker News