{
  "id": "CVE-2021-4034",
  "url": "https://spydr.io/cve/CVE-2021-4034",
  "published": "2022-01-28T20:15:12.193Z",
  "modified": "2026-08-15T04:17:57.927Z",
  "score": 7.8,
  "severity": "high",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "NVD",
  "epss": 0.94345,
  "epss_percentile": 0.99851,
  "exploited": true,
  "kev": {
    "added": "2022-06-27",
    "due": "2022-07-18",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Known",
    "name": "Red Hat Polkit Out-of-Bounds Read and Write Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-4034"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "polkit project",
    "redhat",
    "canonical",
    "suse",
    "oracle",
    "siemens",
    "starwindsoftware"
  ],
  "products": [
    "polkit"
  ],
  "cwes": [
    "CWE-787",
    "CWE-125"
  ],
  "description": "A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it'll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 7.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.html",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://access.redhat.com/security/vulnerabilities/RHSB-2022-001",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2025869",
      "tags": [
        "Issue Tracking",
        "Patch"
      ]
    },
    {
      "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdf",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://www.oracle.com/security-alerts/cpuapr2022.html",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt",
      "tags": [
        "Exploit",
        "Mitigation",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.starwindsoftware.com/security/sw-20220818-0001/",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.suse.com/support/kb/doc/?id=000020564",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.vicarius.io/vsociety/posts/pwnkit-pkexec-lpe-cve-2021-4034",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-4034",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-4034",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}