CriticalCVE-2012-4681

    Oracle Java SE Runtime Environment (JRE) Arbitrary Code Execution Vulnerability (CVE-2012-4681)

    Published Last modified In CISA KEV since Sources: CVE.org

    What is affected, what to do

    Multiple vulnerabilities in the Java Runtime Environment (JRE) component in Oracle Java SE 7 Update 6 and earlier allow remote attackers to execute arbitrary code via a crafted applet that bypasses SecurityManager restrictions by (1) using com.sun.beans.finder.ClassFinder.findClass and leveraging an exception with the forName method to access restricted classes from arbitrary packages such as sun.awt.SunToolkit, then (2) using "reflection with a trusted immediate caller" to leverage the getField method to access and modify private fields, as exploited in the wild in August 2012 using Gondzz.class and Gondvv.class.

    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 1.6.0..1.6.0
    • Oracle JDK eq 1.7.0..1.7.0
    • Oracle JRE eq 1.6.0..1.6.0
    • Oracle JRE eq 1.7.0..1.7.0
    • Redhat Enterprise Linux Desktop eq 6.0..6.0
    • Red Hat Enterprise Linux Extended Update Support (EUS) eq 6.3..6.3
    • Redhat Enterprise Linux Server eq 6.0..6.0
    • Redhat Enterprise Linux Workstation eq 6.0..6.0

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    Metrics

    9.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: CVE.org

    98.5 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.92

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    253.87 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploited
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    9.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.8
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    98.5 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    99.92
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 2 March 2022
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-284

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This flaw is network-reachable without authentication: a crafted applet bypasses the SecurityManager entirely. It was a staple of drive-by exploit kits and remains among the CVEs most likely to be exploited, and CISA flags known use in ransomware campaigns. Today the real risk sits in legacy estate — engineering workstations, hardware management consoles, terminal servers hosting old line-of-business apps, and IE-mode configurations — precisely the IT/OT seams typical of KRITIS environments. Treat any Java 7 install with browser integration and internet access as critical. Isolated systems with no plugin and no web access can follow later, but must be firmly scheduled as part of EoL remediation.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory every JRE/JDK install across clients, terminal servers and VDI golden images. Check HKLM\SOFTWARE\JavaSoft\Java Runtime Environment including WOW6432Node, and on Linux check update-alternatives --list java and the package managers. Java SE 7 Update 6 and earlier are affected.
      • Remove or replace legacy Java 7. Oracle fixed this via the Security Alert for CVE-2012-4681. Java 7 is fully end-of-life, so migrate to a currently supported Java release. Look up the exact version in the vendor advisory.
      • Kill the Java browser plugin now. Remove or block it via browser policy. On newer JREs, also set deployment.webjava.enabled=false in deployment.properties. Modern browsers no longer support NPAPI, so legacy setups such as IE11 or IE-mode with the Java plugin are top priority.
      • Isolate hosts that must keep an old JRE, such as line-of-business apps, HMI/SCADA engineering stations and out-of-band hardware management consoles. Move them into a dedicated VLAN with no direct internet or proxy egress.
      • Run a retrospective compromise check on any machine that browsed the internet with a vulnerable JRE and an active plugin. Hunt in EDR telemetry and proxy logs for Java processes spawning children and for JAR downloads (see detection). Reimage on any hit and reset the user's credentials.

    2. Runbook step 2

      Mitigation layers

      • Network/proxy: Block downloads of application/java-archive, application/x-java-applet, and .jar/.class/.jnlp files from non-approved categories at the web proxy. Maintain an allowlist of internal hosts for business applications.
      • IPS/network signatures: Enable existing signatures for CVE-2012-4681 and Java applet exploit kits (e.g. the Emerging Threats "EXPLOIT_KIT" / Java categories). If the proxy inspects content, scan JARs for the strings Gondzz, Gondvv, sun.awt.SunToolkit and com.sun.beans.finder.ClassFinder.
      • Endpoint hardening: Use AppLocker/WDAC or an EDR block rule to stop java.exe, javaw.exe and jp2launcher.exe from launching cmd.exe, powershell.exe, wscript.exe or rundll32.exe. Block execution from %TEMP% and %APPDATA%.
      • Configuration: Where browser Java is a hard business requirement, deploy a Deployment Rule Set using a signed DeploymentRuleSet.jar. Allow only explicitly approved internal applets and set everything else to block.
      • IAM/least privilege: No web browsing with local admin rights. This matters most on engineering and admin workstations, where legacy JREs tend to live. Successful exploitation inherits the browser user's privileges.

    3. Runbook step 3

      Detection rules

      • Sysmon EID 1 / EDR process ancestry: browser → 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 (FileCreate): a Java process writes .exe or .dll files into %TEMP% or %APPDATA%, typically followed by an EID 1 executing that same file (dropper pattern).
      • Proxy/web logs: JAR fetches with a Java/1.7.0_06-or-older user agent from external, newly registered or uncategorised domains. SPL: index=proxy http_user_agent="*Java/1.7.0_0*" (uri="*.jar" OR content_type="application/java-archive")
      • Zeek files.log/http.log: mime_type == "application/java-archive" from external sources. Run YARA over the extracted JARs for Gondzz.class, Gondvv.class, or the combination ClassFinder + SunToolkit + getField.
      • Inventory as detection: set up a recurring software inventory report (Intune, SCCM, osquery programs) that flags any JRE 7 build as a compliance violation.

    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 the Java Runtime Environment (JRE) component in Oracle Java SE 7 Update 6 and earlier allow remote attackers to execute arbitrary code via a crafted applet that bypasses SecurityManager restrictions by (1) using com.sun.beans.finder.ClassFinder.findClass and leveraging an exception with the forName method to access restricted classes from arbitrary packages such as sun.awt.SunToolkit, then (2) using "reflection with a trusted immediate caller" to leverage the getField method to access and modify private fields, as exploited in the wild in August 2012 using Gondzz.class and Gondvv.class.

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

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    oraclejdk
    • 1.6.0
    • 1.7.0
    • —
    • —
    oraclejre
    • 1.6.0
    • 1.7.0
    • —
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxredhatenterprise_linux_desktop6.0
    Linuxredhatenterprise_linux_eus6.3
    Linuxredhatenterprise_linux_server6.0
    Linuxredhatenterprise_linux_workstation6.0

    Weakness classes (CWE)

    • CWE-284Improper Access Control

      Pillar

      The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

      Entry at MITRE CWE-284

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentchanged
      {"id":"CVE-2012-4681","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-08-05T20:37:22.469362Z"}
      {"id":"CVE-2012-4681","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2022-03-02T00:00:00+00:00"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: active, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentchanged
      {"id":"CVE-2012-4681","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"rapid"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2022-03-02T00:00:00+00:00"}
      {"id":"CVE-2012-4681","role":"CISA Coordinator","options":[{"exploitation":"active"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-08-05T20:37:22.469362Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

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