CriticalCVE-2011-2462

    Adobe Reader and Acrobat Universal 3D Memory Corruption Vulnerability (CVE-2011-2462)

    Published In CISA KEV since Sources: CVE.org

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    What is affected, what to do

    Unspecified vulnerability in the U3D component in Adobe Reader and Acrobat 10.1.1 and earlier on Windows and Mac OS X, and Adobe Reader 9.x through 9.4.6 on UNIX, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via unknown vectors, as exploited in the wild in December 2011.

    The vulnerability is being actively exploited; treat it as a priority. 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
    • Adobe Acrobat PDF Extension (Chrome) lte *..10.1.1
    • Adobe Acrobat Reader lte *..10.1.1
    • Adobe Acrobat Reader lte 9.0..9.4.6

    Not sure whether and how you are affected? Ask a question about this vulnerability

    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

    88.6 %

    EPSS score

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

    Source: FIRST EPSS, percentile 99.78

    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
    228.65 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“.

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    88.6 %
    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.

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    99.78
    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 · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 21 November 2025
    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-787

    Response and mitigation

    Why act now?

    Prioritisation rationale

    A crafted PDF is enough to achieve arbitrary code execution through this flaw. It was historically used in targeted spear-phishing against organisations holding valuable intellectual property, and public exploits have long shipped in mainstream frameworks. As a result, EPSS still rates exploitation as very likely, even though CISA records no ransomware use. Your actual exposure depends almost entirely on whether legacy installs still exist. Typical places to find them are golden images, line-of-business servers, OT and lab systems, and Linux desktops running acroread. Treat any find as critical, because these products are unsupported and carry many other unpatched flaws alongside this one. If the inventory comes back clean, ongoing inventory monitoring is sufficient.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Build the inventory: Use SCCM/Intune, uninstall-registry queries, or dpkg -l | grep -i acroread / rpm -qa | grep -i acro on Linux to find every install of Adobe Reader/Acrobat 10.1.1 or earlier (Windows/macOS) and Adobe Reader 9.0–9.4.6 (UNIX/Linux).
      • Upgrade or replace: A patch is available from the vendor. Look up the exact fixed version in the vendor advisory. The affected product lines (Reader/Acrobat 9.x and X) have been out of support for years. The only durable fix is to migrate to the current supported Acrobat Reader release. Uninstall the legacy versions rather than layering the new release on top.
      • Remove UNIX/Linux leftovers: Adobe Reader 9.x for UNIX is abandoned. Purge acroread packages and replace them with a maintained PDF viewer from the distribution repositories.
      • Isolate hosts you cannot fix: Where a legacy version must stay for business reasons (OT engineering workstations, lab equipment), move those hosts into a segment without mail or internet access. Admit PDFs only through a content-inspecting transfer gateway.
      • Hunt retroactively: Sweep the mail gateway quarantine and mailboxes from recent weeks for PDF attachments that embed U3D objects (see Detection rules). Quarantine any hits and triage the recipients' endpoints.

    2. Runbook step 2

      Mitigation layers

      • Configuration – disable 3D rendering: Clear Preferences → 3D & Multimedia → "Enable playing 3D content". Lock the setting via GPO or the Adobe Customization Wizard under HKLM\SOFTWARE\Policies\Adobe\<product>\<version>\FeatureLockDown, and verify the exact value name (e.g. bEnable3D) in the Adobe Enterprise Toolkit. With 3D disabled, the vulnerable U3D parser is never reached.
      • Configuration – disable JavaScript: Exploits in this class typically rely on embedded JavaScript for heap spraying, so set bEnableJS = 0 in FeatureLockDown. Also enforce Protected Mode/Protected View where the version supports it. Reader 9.x has no sandbox at all.
      • Mail/web gateway: Block PDFs containing /U3D or /3D objects at the mail boundary, or route them to sandbox detonation. Deploy a YARA rule matching /Subtype /U3D together with /JavaScript or /JS at the gateway or MTA content filter. Optionally run inbound PDFs through CDR (content disarm and reconstruction).
      • Endpoint hardening: Stop AcroRd32.exe and Acrobat.exe from spawning child processes. In Defender for Endpoint, use the ASR rule "Block Adobe Reader from creating child processes"; otherwise use an equivalent EDR, AppLocker or WDAC policy. Block executable launches from %TEMP% and %APPDATA%.
      • Least privilege: Never let users open PDFs from admin accounts. Remove local admin rights on workstations to make post-exploitation privilege escalation harder.

    3. Runbook step 3

      Detection rules

      • Sysmon EID 1 / EDR process ancestry: Look for AcroRd32.exe or Acrobat.exe spawning cmd.exe, powershell.exe, wscript.exe, cscript.exe, rundll32.exe, regsvr32.exe or mshta.exe. KQL: DeviceProcessEvents | where InitiatingProcessFileName in~ ("acrord32.exe","acrobat.exe") and FileName in~ ("cmd.exe","powershell.exe","rundll32.exe","regsvr32.exe","mshta.exe","wscript.exe")
      • Sysmon EID 11 / file creation: Watch for the Reader process dropping .exe, .dll or .scr files into %TEMP% or %APPDATA%, often while opening a decoy PDF. Sigma shape: Image|endswith: '\AcroRd32.exe' with TargetFilename|endswith: ['.exe','.dll','.scr'].
      • Windows Application log, Event ID 1000/1001: Look for clusters of AcroRd32.exe or Acrobat.exe crashes right after users open mail attachments. Failed exploitation attempts frequently surface as memory-corruption crashes.
      • Network (Zeek/Suricata): Flag new outbound HTTP or DNS connections that EDR attributes to the Reader process, and beaconing that starts shortly after a PDF is opened. Use Zeek files.log to extract PDFs (mime_type == "application/pdf") and scan them with YARA for /U3D.
      • Inventory as detection: Run a daily check for AcroRd32.exe with a file version at or below 10.1.1 or 9.4.6. Track every hit as an open finding in vulnerability management.

    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

    Unspecified vulnerability in the U3D component in Adobe Reader and Acrobat 10.1.1 and earlier on Windows and Mac OS X, and Adobe Reader 9.x through 9.4.6 on UNIX, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via unknown vectors, as exploited in the wild in December 2011.

    Source: NVD (NIST), cvelistv5, CISA KEV Catalog, 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
    adobeacrobat
    • ≤ 10.1.1
    • —
    adobeacrobat_reader
    • ≤ 10.1.1
    • 9.0 – ≤ 9.4.6
    • —
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-787Out-of-bounds Write

      Base

      The product writes data past the end, or before the beginning, of the intended buffer.

      Entry at MITRE CWE-787

    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

    • lists.opensuse.orgopenSUSE-SU-2012:0087Vendor advisory, x_refsource_SUSE, Broken link
    • adobe.comsupport/security/bulletins/apsb12-01.htmlx_refsource_CONFIRM, Not applicable
    • adobe.comsupport/security/advisories/apsa11-04.htmlx_refsource_CONFIRM, Vendor advisory
    • redhat.comRHSA-2012:0011Vendor advisory, x_refsource_REDHAT, Broken link
    • lists.opensuse.orgSUSE-SU-2012:0086Vendor advisory, x_refsource_SUSE, Broken link
    • adobe.comsupport/security/bulletins/apsb11-30.htmlx_refsource_CONFIRM, Not applicable
    • oval.cisecurity.orgoval:org.mitre.oval:def:14562Vulnerability database, signature, x_refsource_OVAL, Broken link
    • us-cert.govTA11-350AThird-party advisory, x_refsource_CERT, Third-party advisory, US government resource
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2011-2462government-resource, US government resource
    • github.comcisagov/vulnrichment/issues/199Issue tracking, Issue tracking
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