Vulnerability Database

328,409

Total vulnerabilities in the database

CVE-2021-4034

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.

  • Published: Jan 28, 2022
  • Updated: Nov 7, 2025
  • CVE: CVE-2021-4034
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 7.8
  • AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v2:

  • Severity: High
  • Score: 7.2
  • AV:L/AC:L/Au:N/C:C/I:C/A:C
Software From Fixed in
redhat / enterprise_linux_desktop 7.0 7.0.x
redhat / enterprise_linux_workstation 7.0 7.0.x
redhat / enterprise_linux_for_scientific_computing 7.0 7.0.x
redhat / enterprise_linux_server 7.0 7.0.x
redhat / enterprise_linux_for_power_little_endian 7.0 7.0.x
redhat / enterprise_linux_server 6.0 6.0.x
redhat / enterprise_linux_for_power_big_endian 7.0 7.0.x
redhat / enterprise_linux_for_ibm_z_systems 7.0 7.0.x
redhat / enterprise_linux_server_aus 7.3 7.3.x
redhat / enterprise_linux_server_aus 7.4 7.4.x
redhat / enterprise_linux_server_tus 7.6 7.6.x
redhat / enterprise_linux_server_aus 7.6 7.6.x
redhat / enterprise_linux 8.0 8.0.x
redhat / enterprise_linux_server_aus 7.7 7.7.x
redhat / enterprise_linux_server_tus 7.7 7.7.x
redhat / enterprise_linux_eus 8.2 8.2.x
redhat / enterprise_linux_server_tus 8.2 8.2.x
redhat / enterprise_linux_server_aus 8.2 8.2.x
redhat / enterprise_linux_server_tus 8.4 8.4.x
redhat / enterprise_linux_server_aus 8.4 8.4.x
redhat / enterprise_linux_server_update_services_for_sap_solutions 8.2 8.2.x
redhat / enterprise_linux_server_update_services_for_sap_solutions 8.4 8.4.x
redhat / enterprise_linux_server_update_services_for_sap_solutions 8.1 8.1.x
redhat / enterprise_linux_for_power_little_endian_eus 8.2 8.2.x
redhat / enterprise_linux_for_ibm_z_systems_eus 8.2 8.2.x
redhat / enterprise_linux_for_power_little_endian_eus 8.1 8.1.x
redhat / enterprise_linux_for_power_little_endian 8.0 8.0.x
redhat / enterprise_linux_for_ibm_z_systems_eus 8.4 8.4.x
redhat / enterprise_linux_for_ibm_z_systems 8.0 8.0.x
redhat / enterprise_linux_for_power_little_endian_eus 8.4 8.4.x
redhat / enterprise_linux_server_eus 8.4 8.4.x
redhat / enterprise_linux_server_update_services_for_sap_solutions 7.7 7.7.x
redhat / enterprise_linux_server_update_services_for_sap_solutions 7.6 7.6.x
canonical / ubuntu_linux 18.04 18.04.x
canonical / ubuntu_linux 14.04 14.04.x
canonical / ubuntu_linux 20.04 20.04.x
canonical / ubuntu_linux 16.04 16.04.x
canonical / ubuntu_linux 21.10 21.10.x
suse / manager_server 4.1 4.1.x
suse / linux_enterprise_workstation_extension 12-sp5 12-sp5.x
suse / linux_enterprise_desktop 15-sp2 15-sp2.x
suse / enterprise_storage 7.0 7.0.x
suse / manager_proxy 4.1 4.1.x
suse / linux_enterprise_high_performance_computing 15.0-sp2 15.0-sp2.x
suse / linux_enterprise_server 15-sp2 15-sp2.x
oracle / http_server 12.2.1.3.0 12.2.1.3.0.x
oracle / http_server 12.2.1.4.0 12.2.1.4.0.x
oracle / zfs_storage_appliance_kit 8.8 8.8.x
siemens / sinumerik_edge - 3.3.0
siemens / scalance_lpe9403_firmware - 2.0
starwindsoftware / starwind_virtual_san 8-build14338 8-build14338.x
starwindsoftware / command_center 1.0-update3_build5871 1.0-update3_build5871.x
polkit_project / polkit - 121

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.