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May 11, 2022
CVE-2022-26923 - Active Directory Domain Services Elevation of Privilege Vulnerability
THE THREAT Microsoft has disclosed a new vulnerability impacting Active Directory Certificate Services (ADCS) tracked as CVE-2022-26923 (Active Directory Domain Services Elevation of Privilege Vulnerability). If exploited successfully, an authenticated attacker can escalate privileges in environments where ADCS is running on the domain. eSentire is aware of technical details and tooling [2] for…
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eSentire is The Authority in Managed Detection and Response Services, protecting the critical data and applications of 1200+ organizations in 75+ countries from known and unknown cyber threats. Founded in 2001, the company’s mission is to hunt, investigate and stop cyber threats before they become business disrupting events.
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Cybersecurity Leader eSentire Continues Its Commitment to Rigorous Security Standards Earning PCI DSS Certification
Waterloo, ON, May 17, 2022 — eSentire, the Authority in Managed Detection and Response (MDR), maintains one of the most secure and robust IT environments of any MDR provider in the industry. To that end, eSentire today announced that it has received the Payment Card Industry Data Security Standard (PCI DSS) certification, considered one of the most stringent and comprehensive payment card…
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Security advisories — Jan 26, 2022

Polkit Vulnerability Impacting Linux Devices 

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On January 25th, 2022, a new vulnerability impacting Polkit’s pkexec program was disclosed. Polkit’s pkexec is included by default in all major Linux distributions. The vulnerability is tracked as CVE-2021-4034 (CVSS: 7.8) and allows for Local Privilege Escalation. Exploitation would enable a threat actor, with previous access to a vulnerable device, to escalate their privileges to full root privileges.

Exploitation of CVE-2021-4034 has not been identified at this time. eSentire has confirmed that functioning Proof-of-Concept exploit code is publicly available. Organizations are strongly encouraged to ensure that impacted systems are patched as soon as possible, as exploitation is expected in the immediate future.

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What you should do about it

Additional information

Polkit’s pkexec is used to control system-wide privileges in Linux operating systems. It is meant to allow authorized users to run commands as the super user.

Exploitation has been tested and confirmed against Ubuntu, Debian, Fedora, and CentOS Linux distributions. Each impacted Linux distribution will be required to release their own updates to address CVE-2021-4034. Vendor responses can be found in the following links:

This list is expected to expand as distributions address CVE-2021-4034.

Exploits for CVE-2021-4034 are being widely shared by both researchers and threat actors. eSentire assesses, with high confidence, that this vulnerability will be adopted by threat actors for real world exploitation in a matter of days.


[1] https://blog.qualys.com/vulnerabilities-threat-research/2022/01/25/pwnkit-local-privilege-escalation-vulnerability-discovered-in-polkits-pkexec-cve-2021-4034
[2] https://linux.die.net/man/1/pkexec
[3] https://access.redhat.com/security/cve/CVE-2021-4034
[4] https://ubuntu.com/security/CVE-2021-4034
[5] https://security-tracker.debian.org/tracker/CVE-2021-4034

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