Oracle JRE Remote Code Execution Vulnerability (CVE-2013-0422)

What is affected, what to do

Multiple vulnerabilities in Oracle Java 7 before Update 11 allow remote attackers to execute arbitrary code by (1) using the public getMBeanInstantiator method in the JmxMBeanServer class to obtain a reference to a private MBeanInstantiator object, then retrieving arbitrary Class references using the findClass method, and (2) using the Reflection API with recursion in a way that bypasses a security check by the java.lang.invoke.MethodHandles.Lookup.checkSecurityManager method due to the inability of the sun.reflect.Reflection.getCallerClass method to skip frames related to the new reflection API, as exploited in the wild in January 2013, as demonstrated by Blackhole and Nuclear Pack, and a different vulnerability than CVE-2012-4681 and CVE-2012-3174. NOTE: some parties have mapped the recursive Reflection API issue to CVE-2012-3174, but CVE-2012-3174 is for a different vulnerability whose details are not public as of 20130114. CVE-2013-0422 covers both the JMX/MBean and Reflection API issues.

The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.

Affected

• Oracle JDK eq 1.7.0..1.7.0
• Oracle JRE eq 1.7.0..1.7.0
• Canonical Ubuntu Linux eq 12.10..12.10
• OpenSUSE eq 12.2..12.2

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Metrics

Response and mitigation

1. 01

   Runbook step 1

   Immediate response (0-24 h)

   • Inventory: Use software inventory or EDR to find every endpoint running Oracle Java 7 prior to Update 11 (1.7.0_10 or earlier). Also capture any Java 7 install at all, since Java 7 is out of vendor support. Check java -version and the registry keys HKLM\SOFTWARE\JavaSoft\Java Runtime Environment and HKLM\SOFTWARE\WOW6432Node\JavaSoft.
   • Remove rather than patch: The fix shipped in Java 7 Update 11. However, the context notes that the findClass/MBeanInstantiator vector may not have been fully fixed there. Uninstall Java 7 entirely, and replace it with a currently supported Java release only where there is a business need. Look up the exact version in the vendor advisory.
   • Kill the browser plugin now: Untick "Enable Java content in the browser" in the Java Control Panel, or push it centrally through deployment.properties with deployment.webjava.enabled=false and deployment.webjava.enabled.locked. Also block the NPAPI and ActiveX Java plugins in Internet Explorer and Firefox ESR via GPO or policy.
   • Compromise sweep: On hosts that ran a vulnerable Java version with browser use, hunt EDR process trees for java.exe/javaw.exe/jp2launcher.exe spawning child processes (see Detection rules). Isolate any hits immediately.
   • Contain legacy dependencies: Move business apps that genuinely require Java 7 applets (old HMI, KVM or management consoles) onto dedicated jump hosts with no internet access.
2. 02

   Runbook step 2

   Mitigation layers

   • Network/proxy: At the web proxy, block inbound downloads of .jar, .class and .jnlp files, as well as the MIME types application/java-archive and application/x-java-jnlp-file. Allow exceptions only through an allowlist of internal, signed sources.
   • IPS: Enable exploit-kit signatures (Blackhole, Nuclear Pack) and Java applet exploit signatures in Suricata/Snort, for example the Emerging Threats "EXPLOIT_KIT" and "Java Applet" categories. Also add category filtering for newly registered and uncategorised domains.
   • Endpoint hardening: Use AppLocker or WDAC, or EDR custom rules, to stop java.exe/javaw.exe from launching cmd.exe, powershell.exe, wscript.exe or rundll32.exe. Block execution from %TEMP% and %APPDATA%.
   • Java configuration (where Java must stay): Set the security level to "Very High". Use a Deployment Rule Set (DeploymentRuleSet.jar) to allow only explicitly approved, signed applets and block everything else with <action permission="block"/>.
   • Least privilege: Run users without local admin rights to slow down persistence and lateral movement after successful code execution.
3. 03

   Runbook step 3

   Detection rules

   • Sysmon EID 1 / Security 4688 – process ancestry: browser (iexplore.exe, firefox.exe, chrome.exe) → java.exe/javaw.exe/jp2launcher.exe → shell or LOLBin. KQL: DeviceProcessEvents | where InitiatingProcessFileName in~ ("java.exe","javaw.exe","jp2launcher.exe") and FileName in~ ("cmd.exe","powershell.exe","wscript.exe","rundll32.exe","regsvr32.exe")
   • Sysmon EID 11 – file creation: A Java process writes .exe or .dll files into %TEMP% or %APPDATA%. Sigma shape: Image|endswith: '\javaw.exe' with TargetFilename|endswith: ['.exe','.dll'].
   • Proxy logs: A .jar fetch with Content-Type: application/java-archive right after a redirect chain (302/iframe) from a compromised site, followed by a PE download. SPL: index=proxy (uri="*.jar" OR content_type="application/java-archive") | stats count by src_ip, dest_host
   • Java deployment cache: New entries under %USERPROFILE%\AppData\LocalLow\Sun\Java\Deployment\cache\ from unknown hosts, especially unsigned JARs referencing MBeanInstantiator, JmxMBeanServer or MethodHandles (YARA string match).
   • Zeek/Suricata: files.log entries with mime_type == "application/java-archive" from external sources, followed by outbound beaconing from the same host at short, regular intervals.

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2

NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

Read in glossary

Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).

CRA

The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

Read in glossary

Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.

ISO/IEC 27001

ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

Read in glossary

Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

Multiple vulnerabilities in Oracle Java 7 before Update 11 allow remote attackers to execute arbitrary code by (1) using the public getMBeanInstantiator method in the JmxMBeanServer class to obtain a reference to a private MBeanInstantiator object, then retrieving arbitrary Class references using the findClass method, and (2) using the Reflection API with recursion in a way that bypasses a security check by the java.lang.invoke.MethodHandles.Lookup.checkSecurityManager method due to the inability of the sun.reflect.Reflection.getCallerClass method to skip frames related to the new reflection API, as exploited in the wild in January 2013, as demonstrated by Blackhole and Nuclear Pack, and a different vulnerability than CVE-2012-4681 and CVE-2012-3174. NOTE: some parties have mapped the recursive Reflection API issue to CVE-2012-3174, but CVE-2012-3174 is for a different vulnerability whose details are not public as of 20130114. CVE-2013-0422 covers both the JMX/MBean and Reflection API issues. NOTE: it was originally reported that Java 6 was also vulnerable, but the reporter has retracted this claim, stating that Java 6 is not exploitable because the relevant code is called in a way that does not bypass security checks. NOTE: as of 20130114, a reliable third party has claimed that the findClass/MBeanInstantiator vector was not fixed in Oracle Java 7 Update 11. If there is still a vulnerable condition, then a separate CVE identifier might be created for the unfixed issue.

Source: NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

Vendors and products

• Canonical Canonical Ubuntu Linux
• openSUSE OpenSUSE
• Oracle Oracle JDK
• Oracle Oracle Java Runtime Environment (JRE)

References & sources

• rhn.redhat.comRHSA-2013:0156Vendor advisory, x_refsource_REDHAT, Third-party advisory
• malware.dontneedcoffee.com2013/01/0-day-17u10-spotted-in-while-disable.htmlx_refsource_MISC, Third-party advisory
• mandriva.comMDVSA-2013:095Vendor advisory, x_refsource_MANDRIVA, Not applicable
• blog.fuseyism.comindex.php/2013/01/15/security-icedtea-2-1-4-2-2-4-2-3-4-releasedx_refsource_MISC, Broken link
• lists.opensuse.orgopenSUSE-SU-2013:0199Vendor advisory, x_refsource_SUSE, Mailing list, Third-party advisory
• rhn.redhat.comRHSA-2013:0165Vendor advisory, x_refsource_REDHAT, Third-party advisory
• kb.cert.orgVU#625617Third-party advisory, x_refsource_CERT-VN, Third-party advisory, US government resource
• us-cert.govTA13-010AThird-party advisory, x_refsource_CERT, Third-party advisory, US government resource
• partners.immunityinc.comidocs/Java MBeanInstantiator.findClass 0day Analysis.pdfx_refsource_MISC, Broken link
• blog.fireeye.comresearch/2013/01/happy-new-year-from-new-java-zero-day.htmlx_refsource_MISC, Not applicable
• www-304.ibm.comconnections/blogs/PSIRT/entry/oracle_java_7_security_manager_by…x_refsource_MISC, Not applicable
• ubuntu.comUSN-1693-1Vendor advisory, x_refsource_UBUNTU, Third-party advisory
• wiki.mageia.orgen/Support/Advisories/MGASA-2013-0018x_refsource_CONFIRM, Third-party advisory
• immunityproducts.blogspot.ca2013/01/confirmed-java-only-fixed-one-of-two.htmlx_refsource_MISC, Third-party advisory
• threatpost.comen_us/blogs/nasty-new-java-zero-day-found-exploit-kits-already-…x_refsource_MISC, Not applicable
• seclists.org20130110 [SE-2012-01] 'Fix' for Issue 32 exploited by new Java 0-day codeMailing list, x_refsource_BUGTRAQ, Mailing list, Third-party advisory
• oracle.comtechnetwork/topics/security/alert-cve-2013-0422-1896849.htmlx_refsource_CONFIRM, Vendor advisory
• krebsonsecurity.com2013/01/zero-day-java-exploit-debuts-in-crimewarex_refsource_MISC, Third-party advisory
• labs.alienvault.comlabs/index.php/2013/new-year-new-java-zerodayx_refsource_MISC, Broken link, Third-party advisory
• cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2013-0422government-resource, US government resource