CVE-2021-40836 Explained : Impact and Mitigation

A vulnerability affecting F-Secure antivirus engine that can lead to denial-of-service when scanning MS Outlook .pst files remotely.

Understanding CVE-2021-40836

A denial-of-service vulnerability in F-Secure antivirus engine affecting various F-Secure products.

What is CVE-2021-40836?

Affects F-Secure endpoint protection products on Windows, Mac, Linux, Atlant, and Internet Gatekeeper
Remote exploitation can cause denial-of-service in the antivirus engine

The Impact of CVE-2021-40836

Base score: 4.6 (Medium severity)
Attack complexity: Low
Attack vector: Network
User interaction: Required
Availability impact: Low
Confidentiality impact: Low
Integrity impact: None
Privileges required: Low
Scope: Unchanged
More details in the CVSS vector string

Technical Details of CVE-2021-40836

Denial-of-Service (DoS) Vulnerability

Vulnerability Description

Scanning MS Outlook .pst files can trigger denial-of-service
Exploitable remotely leading to denial-of-service

Affected Systems and Versions

F-Secure endpoint protection products on Windows and Mac
F-Secure Linux Security (32-bit) and 64-bit
F-Secure Atlant & F-Secure Internet Gatekeeper
All versions are affected

Exploitation Mechanism

Attack vector: Network
Privileges required: Low
User interaction: Required

Mitigation and Prevention

Immediate Steps to Take

Implement the provided fix through automatic update channel with Capricorn update 2021-12-13_07

Long-Term Security Practices

Regularly update antivirus definitions
Educate users on phishing awareness

Patching and Updates

Apply updates promptly to all affected F-Secure products