Security Advisories

CVE-2021-33602: Denial-of-Service (DoS) Vulnerabilty


Denial-of-service (DoS) of the antivirus engine while unpacking a zip archive file.



FIX: No user action is required. The required fix has been published through the automatic update channel with Capricorn update 2021-09-29_03.

Affected Products

Corporate Products:

  • All F-Secure endpoint protection products on Windows
  • F-Secure Linux Security (32-bit)
  • F-Secure Linux Security 64
  • F-Secure Atlant
  • F-Secure Internet Gatekeeper
  • F-Secure Cloud Protection for Salesforce


  • All supported platforms for the affected products

More Information

A vulnerability affecting the F-Secure antivirus engine was discovered when the engine tries to unpack a zip archive (LZW decompression method), and this can crash the scanning engine. The vulnerability can be exploited remotely by an attacker. A successful attack will result in denial-of-service of the antivirus engine.

This issue was reported to F-Secure through the Vulnerability Reward Program. No known exploit or attack has been seen in the wild.


F-Secure Corporation would like to thank faty420 for bringing this issue to our attention. 

Date Issued: 2021-10-06