How severe is CVE-2021-33602?

CVE-2021-33602 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2021-33602 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33602?

CVE-2021-33602 primarily affects F-secure Atlant. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33602?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-33602 published?

CVE-2021-33602 was published on 2021-10-06 and last updated on 2026-06-17.

CVE-2021-33602

CVE-2021-33602 is a medium-severity vulnerability in F-secure Atlant with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: F-secure Atlant
Published: 2021-10-06
Last modified: 2026-06-17

Description

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 Anti-Virus engine.

Frequently asked questions

What is CVE-2021-33602?: 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 Anti-Virus engine.
How severe is CVE-2021-33602?: CVE-2021-33602 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2021-33602 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33602?: CVE-2021-33602 primarily affects F-secure Atlant. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33602?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-33602 published?: CVE-2021-33602 was published on 2021-10-06 and last updated on 2026-06-17.

References

https://www.f-secure.com/en/business/support-and-downloads/security-advisories

Affected products (4)

cpe:2.3:a:f-secure:atlant:*:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:cloud_protection:*:*:*:*:*:salesforce:*:*
cpe:2.3:a:f-secure:internet_gatekeeper:*:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:linux_security:*:*:*:*:*:*:*:*

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