CriticalCVE-2021-38645

    Open Management Infrastructure Elevation of Privilege Vulnerability (CVE-2021-38645)

    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

    7.8

    Priority

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

    Source: NVD, CVSS v3

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org

    2.7 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 86.0

    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
    198.21 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
    7.8 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
    7.8
    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
    2.7 %
    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
    86.0
    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 4 February 2025

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This is one of the "OMIGOD" flaws in the OMI component that Azure extensions install without most admins noticing, and it lets a low-privileged local user reach root without any user interaction, with full impact on confidentiality, integrity and availability. Attackers use it as a second stage after initial access — a web shell, a hijacked service account, a container escape — or chained with the remote OMI bug; typical targets are Linux workloads in Azure and hybrid servers reporting to Log Analytics. Exploitation likelihood is elevated, while CISA does not flag known ransomware use. If you run a Linux fleet in Azure or feed Sentinel/Defender from Linux hosts, treat this as high priority, especially on multi-user and internet-facing systems; if no OMI package is present anywhere, it is not relevant to you.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Inventory OMI across every Linux host: OMI is silently deployed by Azure VM extensions (Log Analytics/OMS agent, Azure Diagnostics LAD, DSC Extension, Update Management, Container Monitoring Solution, Defender for Cloud/Security Center, Sentinel connectors). Check with dpkg -l omi, rpm -q omi or /opt/omi/bin/omiserver --version. Include on-prem and multi-cloud servers running the Log Analytics agent, plus Azure Stack Hub.
      • Update the OMI package: Patch available from the vendor — look up the fixed version in the vendor advisory (MSRC entry for CVE-2021-38645 / OMI GitHub release). Do not assume extension auto-update has done it; re-verify the installed version afterwards.
      • Review local accounts on affected hosts: Exploitation needs a low-privileged local foothold. Disable or remove stale accounts, unknown SSH keys in ~/.ssh/authorized_keys, and interactive shells on service accounts (web, app, container users).
      • Patch hosts with existing footholds first: Multi-user servers, jump hosts and boxes running internet-facing apps are where an attacker most plausibly already has the low-privilege access needed to escalate to root.
      • Rule out the OMIGOD chain: Check whether OMI listens remotely on TCP 5985/5986/1270. If so, block those ports immediately via NSG or host firewall — the related remote code execution flaw in the same component turns this into a full compromise chain.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: Default-deny inbound TCP 5985, 5986 and 1270 to Linux VMs via Azure NSG, Azure Firewall or perimeter firewall; allow only explicitly required management sources.
      • Lock down the local OMI socket: Verify permissions on /var/opt/omi/run/ and the omiserver.sock Unix domain socket so non-root users cannot write to it. Where OMI isn't functionally needed, remove the extension and disable the service (systemctl disable --now omid).
      • Endpoint hardening: Run AppArmor/SELinux in enforcing mode; use EDR policy to block — or at minimum alert on — shells spawned by omiagent/omiengine.
      • IAM / least privilege: Restrict interactive logins on Azure VMs to named admins (Entra ID login for Linux, Just-in-Time VM access from Defender for Cloud). Give service accounts /usr/sbin/nologin.
      • Configuration management: Enforce a minimum OMI package version with Azure Policy or your CM tooling (Ansible, Puppet, DSC) and report drift.

    3. Runbook step 3

      Detection rules

      • auditd process execution under OMI: -a always,exit -F arch=b64 -S execve -F uid=0 -k omi_exec, correlated with parent omiagent/omiengine; alert on children such as sh, bash, python, curl, wget, nc.
      • EDR process ancestry: Chain omiserver → omiengine → omiagent → /bin/sh running as root where the originating request came from a non-root user. KQL (Defender for Endpoint): DeviceProcessEvents | where InitiatingProcessFileName in~ ("omiagent","omiengine") | where FileName in~ ("sh","bash","dash","python","python3","perl").
      • Account and persistence changes: New UID 0 accounts or edits to /etc/passwd, /etc/sudoers, /root/.ssh/authorized_keys shortly after OMI socket access; auditd watch: -w /var/opt/omi/run/ -p rwa -k omi_socket.
      • Network telemetry (Zeek/Suricata): Unusual HTTP POSTs to /wsman on 5985/5986/1270, especially lacking an Authorization header — a sign of the remote sibling bug and possible chaining.
      • Sigma shape: logsource: linux/process_creation; selection: ParentImage|endswith: ['/omiagent','/omiengine']; filter: Image|endswith: ['/omicli','/omiagent']; condition: selection and not filter.

    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_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-2021-38645x_refsource_MISC, x_transferred
    • Microsoft Security Update GuideOpen Management Infrastructure Elevation of Privilege VulnerabilityVendor advisory, Patch
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2021-38645government-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_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-2021-38645 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-2021-38645
      Referenceremoved
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38645
      —
      Reference typeremoved
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38645 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

    Embed badge

    Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.

    Badge preview for CVE-2021-38645
    <a href="https://intel.neosec.eu/en/cve/CVE-2021-38645"><img src="https://intel.neosec.eu/badge/cve/CVE-2021-38645.svg?lang=en" alt="CVE-2021-38645 – NEOSEC Intel" height="20"></a>