CVE-2013-0431

Java normally places downloaded Java content behind a safety barrier. This flaw can let a person who is tricked into opening malicious content help an attacker slip past that barrier, like a visitor being allowed through a building’s reception desk with a forged pass.

This matters to you if you use or run Java Runtime Environment 7 on employee computers, servers, or business applications. It is especially relevant where staff can open Java content from outside sources; an attacker needs a user to interact with malicious content.

Attackers are already exploiting this flaw in ransomware campaigns. Treat this as urgent: the U.S. government required affected federal agencies to remediate it by June 15, 2022, and any remaining unpatched Java 7 installation should be addressed now.

Confirm exposure by inventorying installed Java runtimes on endpoints and servers, including application-bundled runtimes, and identify Oracle Java SE 7 through Update 11 and OpenJDK 7 installations. For Oracle Java SE 7, target Update 13 or later; for OpenJDK 7, use the patched package released by the operating-system vendor, since the supplied findings do not provide a single fixed package version for every distribution.

Test the update with applications that depend on Java before broad deployment. If an application cannot be updated promptly, remove or disable its Java browser integration where possible, restrict use of that system to trusted content, and isolate it from untrusted web access. CISA’s KEV remediation due date was 2022-06-15.

Monitor endpoint and web-filtering records for users opening unexpected Java content, unusual Java process launches, and follow-on malware activity on previously exposed systems.

CVSS 3.1 score: 5.3 (Medium). The reported weakness is an unspecified Java security-sandbox bypass associated with JMX (CWE-693; NVD-CWE-Other). The technical description identifies a user-assisted remote attack path. CISA KEV lists the vulnerability as exploited in ransomware campaigns, which confirms real-world exploitation; no public exploit code is on record. EPSS is high and flat, but its percentage is omitted because confirmed exploitation takes precedence.