Denial-of-Service (DoS) Vulnerability

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 following person for bringing this issue to our attention.



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

  • Fixed
  • Risk level

  • Medium
  • 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
  • Platforms

  • All supported platforms for the affected products
  • Date issued

  • 6/10/2021
  • Security advisories
  • 2021
  • Medium