How severe is CVE-2021-1404?

CVE-2021-1404 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-2021-1404 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1404?

CVE-2021-1404 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-2021-1404?

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-2021-1404 published?

CVE-2021-1404 was published on 2021-04-08 and last updated on 2026-06-17.

CVE-2021-1404

CVE-2021-1404 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Clamav
Published: 2021-04-08
Last modified: 2026-06-17

Description

A vulnerability in the PDF parsing module in Clam AntiVirus (ClamAV) Software versions 0.103.0 and 0.103.1 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper buffer size tracking that may result in a heap buffer over-read. An attacker could exploit this vulnerability by sending a crafted PDF file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to crash, resulting in a denial of service condition.

Frequently asked questions

What is CVE-2021-1404?: A vulnerability in the PDF parsing module in Clam AntiVirus (ClamAV) Software versions 0.103.0 and 0.103.1 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper buffer size tracking that may result in a heap buffer over-read. An attacker could exploit this vulnerability by sending a crafted PDF file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to crash, resulting in a denial of service condition.
How severe is CVE-2021-1404?: CVE-2021-1404 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-2021-1404 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1404?: CVE-2021-1404 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-2021-1404?: 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-2021-1404 published?: CVE-2021-1404 was published on 2021-04-08 and last updated on 2026-06-17.

References

https://blog.clamav.net/2021/04/clamav-01032-security-patch-release.html

Affected products (2)

cpe:2.3:a:clamav:clamav:0.103.0:*:*:*:*:*:*:*
cpe:2.3:a:clamav:clamav:0.103.1:*:*:*:*:*:*:*

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