CVE-2021-44747Network attack vector

Anti-virus engine crash via fuzzed file scanning

Published Mar 1, 2022 · Updated Aug 4, 2024

Denial-of-service in F-Secure Linux Security Fmlib allows remote attackers to interrupt the anti-virus engine by submitting fuzzed files for scanning. The Fmlib scanning component crashes when processing specially crafted fuzzed files, stopping the anti-virus engine. Exploitation requires delivery of a file that reaches scanning; the documented consequence is service interruption without confidentiality or integrity impact.

CVSS severity6.5
Medium
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial-of-service in F-Secure Linux Security Fmlib allows remote attackers to interrupt the anti-virus engine by submitting fuzzed files for scanning. The Fmlib scanning component crashes when processing specially crafted fuzzed files, stopping the anti-virus engine. Exploitation requires delivery of a file that reaches scanning; the documented consequence is service interruption without confidentiality or integrity impact.

The record

CVE
CVE-2021-44747
Published
Mar 1, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.6F-SecureCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:L
4.3NVDAV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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