Four New Apache Struts Flaws Open Door to Remote Code Execution, DoS and Data Leaks

Four security flaws in the Apache Struts Java framework have been detailed in recent advisories, giving attackers the ability to run arbitrary code, disrupt services or expose data across user accounts.

The vulnerabilities affect distinct components of the framework: an outdated action‑mapping mechanism, a decimal‑rendering routine, the processing of RESTful requests, and an additional module whose description was truncated in the original notice. Each flaw can be triggered remotely, allowing malicious actors to bypass typical authentication checks.

Struts powers a wide range of enterprise web applications, from internal portals to public‑facing services. Organizations that continue to run legacy versions are especially exposed, as the affected code paths are often left unchanged in older deployments. The risk is amplified by the framework's deep integration with Java servlet containers, meaning a successful exploit can compromise the underlying server.

Security experts recall the 2017 breach of a major credit‑reporting agency that hinged on an unpatched Struts vulnerability, a reminder that even well‑known frameworks can become attack vectors when updates lag. The current set of advisories arrives at a time when many firms are still modernizing legacy systems, creating a narrow window for potential exploitation.

The Apache Software Foundation has responded by publishing patches for the identified issues and urging users to upgrade immediately. Vendors that bundle Struts in their product suites are also being asked to release updated components. In the meantime, administrators are advised to apply temporary mitigations such as disabling the vulnerable modules, tightening input validation and monitoring network traffic for suspicious patterns.

Analysts expect that threat actors will probe for vulnerable installations soon after the advisories become public. Companies that depend on Struts are therefore urged to conduct rapid inventory checks, verify their version numbers and apply the fixes without delay. The episode underscores the broader challenge of maintaining security hygiene in complex, layered software stacks, where a single outdated library can jeopardize an entire organization.