How severe is CVE-2021-1405?

CVE-2021-1405 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-1405 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1405?

CVE-2021-1405 primarily affects Clamav. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1405?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-1405 published?

CVE-2021-1405 was published on 2021-04-08 and last updated on 2026-06-17.

CVE-2021-1405

CVE-2021-1405 is a high-severity vulnerability in Clamav with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-909.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-909
Affected product: Clamav
Published: 2021-04-08
Last modified: 2026-06-17

Description

A vulnerability in the email parsing module in Clam AntiVirus (ClamAV) Software version 0.103.1 and all prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper variable initialization that may result in an NULL pointer read. An attacker could exploit this vulnerability by sending a crafted email to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process crash, resulting in a denial of service condition.

Frequently asked questions

What is CVE-2021-1405?: A vulnerability in the email parsing module in Clam AntiVirus (ClamAV) Software version 0.103.1 and all prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper variable initialization that may result in an NULL pointer read. An attacker could exploit this vulnerability by sending a crafted email to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process crash, resulting in a denial of service condition.
How severe is CVE-2021-1405?: CVE-2021-1405 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-1405 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1405?: CVE-2021-1405 primarily affects Clamav. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1405?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-1405 published?: CVE-2021-1405 was published on 2021-04-08 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:clamav:clamav:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

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