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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 18 Jul 2022. Known ransomware use
Enterprise Linux Server Update Services For Sap SolutionsApplication · Redhat

CVE-2021-4034

HIGH · 7.8 CVSS v3.1 Published 2022-01-28
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
96/100
Remediation priority · Urgent
In the wild Ransomware High EPSS Public exploit Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A local privilege escalation vulnerability in polkit's pkexec utility stems from incorrect handling of calling parameters, causing the program to attempt execution of environment variables as commands. An unprivileged attacker can craft malicious environment variables to induce pkexec into executing arbitrary code with elevated privileges.

MitigationApply the relevant security patch for polkit (version 0.120 or later recommended) or update the operating system packages. As a temporary workaround, the setuid bit can be removed from pkexec until the patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Enterprise Linux Server Update Services For Sap SolutionsApplication
Affected:= 7.6= 7.7= 8.1= 8.2= 8.4
Enterprise LinuxOperating system
Affected:= 8.0
Enterprise Linux DesktopOperating system
Affected:= 7.0
Enterprise Linux EusOperating system
Affected:= 8.2
Enterprise Linux For Ibm Z SystemsOperating system
Affected:= 7.0= 8.0
Enterprise Linux For Ibm Z Systems EusOperating system
Affected:= 8.2= 8.4
Enterprise Linux For Power Big EndianOperating system
Affected:= 7.0
Enterprise Linux For Power Little EndianOperating system
Affected:= 7.0= 8.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify pkexec exists on the system
    Run `ls -l /usr/bin/pkexec` to confirm the pkexec binary is present
    Affected if The file exists and is located at /usr/bin/pkexec
  2. Confirm pkexec has setuid permissions
    Check the output of `ls -l /usr/bin/pkexec` for the setuid bit (the 's' in permissions like -rwsr-xr-x)
    Affected if The permissions show 'rwsr-xr-x' (with the 's' bit set), indicating pkexec runs with root privileges and could be exploited for privilege escalation
  3. Determine the installed polkit version
    Run `rpm -q polkit` to retrieve the installed polkit package version
    Affected if The version matches one of the affected RHEL versions listed: 7.6, 7.7, 8.0, 8.1, 8.2, 8.4 for the corresponding RHEL variants (Server, Desktop, EUS, for IBM Z Systems, for Power Big Endian, for Power Little Endian)
  4. Check pkexec version directly if available
    Run `pkexec --version` to see the version number reported by the utility itself
    Affected if The reported version matches the affected versions listed for RHEL products

A user is affected if pkexec is present with the setuid bit set and the installed polkit version matches one of the specific RHEL versions listed in the affected products (7.6, 7.7, 8.0, 8.1, 8.2, 8.4 for the respective RHEL variants).

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch bugzilla.redhat.com →
Interim mitigation

Apply the relevant security patch for polkit (version 0.120 or later recommended) or update the operating system packages. As a temporary workaround, the setuid bit can be removed from pkexec until the patch is applied.

Recommended fix High confidence

polkit-0.112-14.el7 or later (RHEL 7.x) | polkit-0.115-11.el8 or later (RHEL 8.x)

  1. Check the current polkit version installed: rpm -qa | grep polkit
  2. Update the polkit package to the patched version using: yum update polkit (RHEL 7) or dnf update polkit (RHEL 8)
  3. After the update completes, verify the installed version matches the patched release: rpm -qa | grep polkit
  4. Reboot the system to ensure all pkexec processes are using the patched binary, or restart any running services that use polkit

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Enterprise Linux Server Update Services For Sap Solutions Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-4034 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data