CriticalCVE-2021-38649

    Open Management Infrastructure Elevation of Privilege Vulnerability (CVE-2021-38649)

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

    What is affected, what to do

    Open Management Infrastructure Elevation of Privilege Vulnerability

    The vulnerability is being actively exploited; treat it as a priority. Update open_management_infrastructure to version 1.6.8-1. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Microsoft Azure Automation State Configuration, DSC Extension gte 2.0.0..*
    • Microsoft Azure Automation Update Management gte 1.0.0..*
    • Microsoft Azure Diagnostics (LAD) gte 3.0.0..*
    • Microsoft Azure Security Center gte 1.0.0..*
    • Microsoft Azure Sentinel gte 1.0.0..*
    • Microsoft Azure Stack Hub gte 1.0.0..*
    • Microsoft Container Monitoring Solution gte 1.0.0..*
    • Microsoft Log Analytics Agent gte 1.0.0..*
    • Microsoft Open Management Infrastructure gte 16.0..*
    • Microsoft System Center Operations Manager (SCOM) gte 1.0.0..*

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

    Metrics

    7.0

    Priority

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

    Source: NVD, CVSS v3

    7.0

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org

    2.9 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 86.8

    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
    195.26 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 exploitedSource: ANSSI / CERT-FR How we classify
    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
    7.0 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
    7.0
    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
    2.9 %
    Moderate — model estimates 1-10% exploitation likelihood.
    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
    86.8
    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

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This is a local, higher-complexity flaw, but successful exploitation yields full root on the host. It landed on KEV through the OMIGOD campaigns, where attackers chained the OMI bugs with remote access to take over Azure Linux VMs for cryptomining and botnets such as Mirai variants. CISA does not flag ransomware use, but exploitation likelihood is elevated relative to most CVEs. Rate it high for any organisation running Linux workloads in Azure or under SCOM management, because OMI is frequently present without anyone knowing. Escalate to critical where OMI ports are reachable externally or where hosts are multi-user.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory every Linux VM running OMI. The affected Azure extensions (Log Analytics Agent, LAD, DSC, Update Management, Container Monitoring, Defender/Security Center, Sentinel) silently install OMI. Check with dpkg -l omi or rpm -qa omi; affected hosts will have /opt/omi/bin/omiserver. Use Azure Resource Graph or Defender for Cloud to sweep the whole fleet.
      • Apply the vendor fix for OMI. A patch is available from the vendor; look up the exact version in the Microsoft Security Update Guide entry for CVE-2021-38649 or in the microsoft/omi GitHub releases. Extensions do not always auto-update, so upgrade the package and extension manually. This includes Azure Stack Hub and on-prem or hybrid hosts.
      • Remove orphaned OMI installs. If a host has been migrated to Azure Monitor Agent or no longer needs the extension, uninstall it. An unused root daemon is pure attack surface.
      • Review local accounts on affected hosts. Exploitation requires a low-privileged local foothold. Hunt for unknown users, rogue authorized_keys entries, and compromised web-app or container service accounts.
      • Treat the sibling bugs together. This CVE is part of the "OMIGOD" set alongside CVE-2021-38647, an unauthenticated RCE. Immediately close external access to OMI ports 5985, 5986 and 1270.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Add NSG and firewall rules denying inbound TCP 5985, 5986 and 1270 to Linux VMs. Allow exceptions only for documented management sources such as SCOM servers. This breaks the remote-foothold-to-root chain.
      • Host hardening: Verify permissions on /var/opt/omi/run/omiserver.sock and /var/opt/omi/; non-root users must not have write access. Where feasible, confine socket access to the agent processes with AppArmor or SELinux.
      • IAM/least privilege: Minimise interactive shell access on workload VMs. Run web and application service accounts with nologin. Never mount /var/opt/omi into containers.
      • Configuration: If remote management is not required, set httpport/httpsport to 0 in /etc/opt/omi/conf/omiserver.conf and restart the service.
      • IPS: Enable Suricata/Snort OMIGOD signatures for HTTP POST to /wsman, especially requests with no Authorization header and ExecuteShellCommand in the body. These flag the remote half of an attack chain.

    3. Runbook step 3

      Detection rules

      • EDR process ancestry: Alert when omiengine or omiagent spawns a shell or interpreter (sh, bash, python, perl, curl, wget) as UID 0 outside known agent behaviour. Sigma shape: ParentImage|endswith: '/omiagent' and Image|endswith: ['/sh','/bash','/python3'].
      • auditd: Deploy -w /var/opt/omi/run/omiserver.sock -p rwa -k omi_sock plus -a always,exit -F arch=b64 -S execve -F euid=0 -F auid>=1000 -k priv_esc. Alert on socket access by a non-root auid followed by an execve with euid=0.
      • Microsoft Sentinel (KQL): DeviceProcessEvents | where InitiatingProcessFileName in~ ("omiagent","omiengine") and FileName in~ ("bash","sh","python3","curl","wget").
      • Network telemetry (Zeek): Flag connections to 5985, 5986 or 1270 from unapproved sources. Also flag http.log entries with URI /wsman and no authentication.
      • Post-escalation persistence: Watch for new files in /etc/cron.d/, changes to /root/.ssh/authorized_keys, or new systemd units shortly after OMI socket access. Correlate these on a single timeline.

    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

    Open Management Infrastructure Elevation of Privilege Vulnerability

    Source: CISA KEV Catalog, NVD (NIST), cvelistv5, 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
    MicrosoftAzure Automation State Configuration, DSC Extension
    • ≥ 2.0.0
    • —
    MicrosoftAzure Automation Update Management
    • ≥ 1.0.0
    • —
    MicrosoftAzure Diagnostics (LAD)
    • ≥ 3.0.0
    • —
    MicrosoftAzure Security Center
    • ≥ 1.0.0
    • —
    MicrosoftAzure Sentinel
    • ≥ 1.0.0
    • —
    MicrosoftAzure Stack Hub
    • ≥ 1.0.0
    • —
    MicrosoftContainer Monitoring Solution
    • ≥ 1.0.0
    • —
    MicrosoftLog Analytics Agent
    • ≥ 1.0.0
    • —
    MicrosoftOpen Management Infrastructure
    • ≥ 16.0
    • —
    MicrosoftSystem Center Operations Manager (SCOM)
    • ≥ 1.0.0
    • —
    microsoftazure_automation_state_configuration
    • —
    • —
    microsoftazure_automation_update_management
    • —
    • —
    microsoftazure_diagnostics_\(lad\)
    • —
    • —
    microsoftazure_open_management_infrastructure
    • —
    • —
    microsoftazure_security_center
    • —
    • —
    microsoftazure_sentinel
    • —
    • —
    microsoftazure_stack_hub
    • —
    • —
    microsoftcontainer_monitoring_solution
    • —
    • —
    microsoftlog_analytics_agent
    • —
    • —
    microsoftopen_management_infrastructure
    • < 1.6.8-1
    • 1.6.8-1
    microsoftsystem_center_operations_manager
    • —
    • —

    Vendors and products

    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
    ANSSI / CERT-FRLicence Ouverte 2.0, as of CERTFR-2021-ALE-020 – [Maj] Multiples vulnérabilités dans Microsoft Azure Open Management Infrastructure (clôturée 2022-01-05) (opens in a new tab)cert.cyber.gouv.fractively exploited

    References & sources

    • portal.msrc.microsoft.comen-US/security-guidance/advisory/CVE-2021-38649x_refsource_MISC, x_transferred
    • Microsoft Security Update GuideOpen Management Infrastructure Elevation of Privilege VulnerabilityVendor advisory, Patch
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2021-38649government-resource
    • cert.cyber.gouv.frANSSI / CERT-FR: CERTFR-2021-ALE-020 – [Maj] Multiples vulnérabilités dans Microsoft Azure Open Management Infrastructure (clôturée 2022-01-05)cert-fr

    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. NVD analysis modifiedNVD

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationchanged
      OR *cpe:2.3:a:microsoft:system_center_operations_manager:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_automation_state_configuration:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_automation_update_management:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_diagnostics_(lad):-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_open_management_infrastructure:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_security_center:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_sentinel:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_stack_hub:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:container_monitoring_solution:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:log_analytics_agent:-:*:*:*:*:*:*:*
      OR *cpe:2.3:a:microsoft:system_center_operations_manager:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_automation_state_configuration:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_automation_update_management:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_diagnostics_(lad):-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_open_management_infrastructure:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_security_center:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_sentinel:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:azure_stack_hub:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:container_monitoring_solution:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:log_analytics_agent:-:*:*:*:*:*:*:* *cpe:2.3:a:microsoft:open_management_infrastructure:*:*:*:*:*:*:*:* versions up to (excluding) 1.6.8-1
      Reference typeadded
      —
      Microsoft Corporation: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38649 Types: Patch, Vendor Advisory

      Source identifier: nvd@nist.gov

    2. Record modifiedMicrosoft

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38649
      Referenceremoved
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38649
      —
      Reference typeremoved
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38649 Types: Patch, Vendor Advisory
      —
      Affected versions (publisher)changed
      Open Management Infrastructure, System Center Operations Manager (SCOM), Azure Automation State Configuration, DSC Extension (+7)
      Azure Automation State Configuration, DSC Extension, Azure Automation Update Management, Azure Diagnostics (LAD) (+7)

      Source identifier: secure@microsoft.com

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