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NVD / CVE Program· CNA redhat

CVE-2021-4034: A local privilege escalation vulnerability was found on polkit's pkexec utility.

Noroxi assessment

Priority: Now (action score 89/100)

  • CISA has confirmed exploitation in the wild (Jun 27, 2022); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Jul 18, 2022.
  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 94.9% (FIRST EPSS); higher than 99.8% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: polkit (AlmaLinux:8) 0.115-13.el8_5.2; polkit-devel (AlmaLinux:8) 0.115-13.el8_5.2; polkit-docs (AlmaLinux:8) 0.115-13.el8_5.2.
  • Mentioned 4 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Upgrade to polkit (AlmaLinux:8) 0.115-13.el8_5.2; polkit-devel (AlmaLinux:8) 0.115-13.el8_5.2; polkit-docs (AlmaLinux:8) 0.115-13.el8_5.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

HighCVSS 7.8 · v3.1KEVWeaponized Fix available
Published
Jan 28, 2022
Updated
Aug 15, 2026
EPSS
94.9% · 99th percentile

Report tools

JSON

Action score

89

Now

Patch today or shut off access.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
28 / 30 · 94.9%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jun 27, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jul 18, 2022.

Known to be used in ransomware campaigns.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
polkit projectpolkit
redhatenterprise linux server update services for sap solutions
redhatenterprise linux
redhatenterprise linux desktop
redhatenterprise linux eus
redhatenterprise linux for ibm z systems
redhatenterprise linux for ibm z systems eus
redhatenterprise linux for power big endian
redhatenterprise linux for power little endian
redhatenterprise linux for power little endian eus
redhatenterprise linux for scientific computing
redhatenterprise linux server

and 19 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux14.04
  • canonical ubuntu linux16.04
  • canonical ubuntu linux18.04
  • canonical ubuntu linux20.04
  • canonical ubuntu linux21.10
  • oracle http server12.2.1.3.0
  • oracle http server12.2.1.4.0
  • oracle zfs storage appliance kit8.8
  • polkit project polkitbefore 121
  • redhat enterprise linux8.0
  • redhat enterprise linux desktop7.0
  • redhat enterprise linux eus8.2
  • redhat enterprise linux for ibm z systems7.0
  • redhat enterprise linux for ibm z systems8.0
  • redhat enterprise linux for ibm z systems eus8.2
  • redhat enterprise linux for ibm z systems eus8.4
  • redhat enterprise linux for power big endian7.0
  • redhat enterprise linux for power little endian7.0
  • redhat enterprise linux for power little endian8.0
  • redhat enterprise linux for power little endian eus8.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a polkit

    • allaffected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8polkitbefore 0.115-13.el8_5.20.115-13.el8_5.2
AlmaLinux:8polkit-develbefore 0.115-13.el8_5.20.115-13.el8_5.2
AlmaLinux:8polkit-docsbefore 0.115-13.el8_5.20.115-13.el8_5.2
AlmaLinux:8polkit-libsbefore 0.115-13.el8_5.20.115-13.el8_5.2
Debian:10policykit-1before 0.105-25+deb10u10.105-25+deb10u1
Debian:11policykit-1before 0.105-31+deb11u10.105-31+deb11u1
Debian:12policykit-1before 0.105-31.10.105-31.1
Debian:9policykit-1before 0.105-18+deb9u20.105-18+deb9u2
openSUSE:Leap 15.3polkitbefore 0.116-3.6.10.116-3.6.1
openSUSE:Tumbleweedpolkitbefore 0.120-2.10.120-2.1
Red Hat:enterprise_linux:7::clientpolkitbefore 0:0.112-26.el7_9.10:0.112-26.el7_9.1
Red Hat:enterprise_linux:7::clientpolkit-debuginfobefore 0:0.112-26.el7_9.10:0.112-26.el7_9.1
Red Hat:enterprise_linux:7::clientpolkit-develbefore 0:0.112-26.el7_9.10:0.112-26.el7_9.1
Red Hat:enterprise_linux:7::clientpolkit-docsbefore 0:0.112-26.el7_9.10:0.112-26.el7_9.1
Red Hat:enterprise_linux:7::hypervisorredhat-virtualization-hostbefore 0:4.3.21-20220126.0.el7_90:4.3.21-20220126.0.el7_9
Red Hat:enterprise_linux:7::hypervisorredhat-virtualization-host-image-updatebefore 0:4.3.21-20220126.0.el7_90:4.3.21-20220126.0.el7_9
Red Hat:enterprise_linux:8::baseospolkitbefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:enterprise_linux:8::baseospolkit-debuginfobefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:enterprise_linux:8::baseospolkit-debugsourcebefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:enterprise_linux:8::baseospolkit-develbefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:enterprise_linux:8::baseospolkit-docsbefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:enterprise_linux:8::baseospolkit-libsbefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:enterprise_linux:8::baseospolkit-libs-debuginfobefore 0:0.115-13.el8_5.10:0.115-13.el8_5.1
Red Hat:rhel_aus:7.3::serverpolkitbefore 0:0.112-12.el7_3.10:0.112-12.el7_3.1

+47

Same product

polkit project: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-3560It was found that polkit could be tricked into bypassing the credential checks for D-Bus requests, elevating the privileges of the requestorKEV
    68This week
  • CVE-2018-19788A flaw was found in PolicyKit (aka polkit) 0.115 that allows a user with a uid greater than INT_MAX to successfully execute any systemctl co
    38Monitor
  • CVE-2019-6133In PolicyKit (aka polkit) 0.115, the "start time" protection mechanism can be bypassed because fork() is not atomic, and therefore authoriza
    26Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2015-3255Oct 26, 2015 · The polkit_backend_action_pool_init function in polkitbackend/polkitbackendactionpool.c in PolicyKit (aka polkit) before 0.113 might allow l
    18Monitor
  • ← EarlierCVE-2015-3256Oct 26, 2015 · PolicyKit (aka polkit) before 0.113 allows local users to cause a denial of service (memory corruption and polkitd daemon crash) and possibl
    18Monitor
  • Later →CVE-2021-4115Feb 21, 2022 · There is a flaw in polkit which can allow an unprivileged user to cause polkit to crash, due to process file descriptor exhaustion.
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:polkit0.115-13.el8_5.2 · AlmaLinux:8Package registry (OSV)
almalinux:polkit-devel0.115-13.el8_5.2 · AlmaLinux:8Package registry (OSV)
almalinux:polkit-docs0.115-13.el8_5.2 · AlmaLinux:8Package registry (OSV)
almalinux:polkit-libs0.115-13.el8_5.2 · AlmaLinux:8Package registry (OSV)
debian:policykit-10.105-31.1 · Debian:12Package registry (OSV)
opensuse:polkit0.116-3.6.1 · openSUSE:Leap 15.3Package registry (OSV)
red hat:polkit0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:polkit-debuginfo0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:polkit-debugsource0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:polkit-desktop-policy0:0.96-11.el6_10.2 · Red Hat:rhel_els:6Package registry (OSV)
red hat:polkit-devel0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:polkit-docs0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:polkit-libs0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:polkit-libs-debuginfo0:0.115-11.el8_2.2 · Red Hat:rhel_eus:8.2::baseosPackage registry (OSV)
red hat:redhat-virtualization-host0:4.3.21-20220126.0.el7_9 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:redhat-virtualization-host-image-update0:4.3.21-20220126.0.el7_9 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
rocky linux:polkit0:0.115-13.el8_5.1 · Rocky Linux:8Package registry (OSV)
suse:polkit0.113-5.24.1 · SUSE:HPE Helion OpenStack 8Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×1
  • Proof-of-concept repository on GitHub ×50

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entrylocal2022-01-27
Metasploit moduleexploit/linux/local/cve_2021_4034_pwnkit_lpe_pkexecLocal Privilege Escalation in polkits pkexecexploit2022-01-25
Proof-of-concept repository on GitHubstars:742022-01-25
Proof-of-concept repository on GitHubstars:20472022-01-25
Proof-of-concept repository on GitHubstars:62022-01-26
Proof-of-concept repository on GitHubstars:22022-01-26
Proof-of-concept repository on GitHubstars:11712022-01-26
Proof-of-concept repository on GitHubstars:82022-01-26
Proof-of-concept repository on GitHubstars:1142022-01-26
Proof-of-concept repository on GitHubstars:592022-01-26
Proof-of-concept repository on GitHubstars:362022-01-26
Proof-of-concept repository on GitHubstars:912022-01-26

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-4 d
  2. Metasploit-4 d
  3. Published
  4. CISA KEV+149 d
  5. TodayOct 29, 2026+1734 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records