CVE-2021-33572Network attack vector

Antivirus engine crash via malformed package scanning

Published Jun 21, 2021 · Updated Sep 16, 2024

Denial of service in F-Secure Linux Security allows remote attackers to crash the FSAVD antivirus engine with a crafted file. FSAVD dereferences a null pointer while scanning oversized packages or fuzzed files, terminating the antivirus engine. The file must reach an affected scanning workflow; the public record does not identify the parser or explain how remote delivery is accepted.

CVSS severity3.5
Low
EPSS probability0.68%
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 allows remote attackers to crash the FSAVD antivirus engine with a crafted file. FSAVD dereferences a null pointer while scanning oversized packages or fuzzed files, terminating the antivirus engine. The file must reach an affected scanning workflow; the public record does not identify the parser or explain how remote delivery is accepted.

The record

CVE
CVE-2021-33572
Published
Jun 21, 2021
Updated
Sep 16, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.5F-SecureCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
4.0NIST NVDAV:N/AC:L/Au:S/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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