HOMEVULNERABILITIESCVE-2021-1405
HIGH

CVE-2021-1405

CWE-120Published: April 8, 2021· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-1405 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

clamav1 product(s)
clamav
Debian1 product(s)
debian linux
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://blog.clamav.net/2021/04/clamav-01032-security-patch-release.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/04/msg00012.html
ADVISORYhttps://security.gentoo.org/glsa/202104-07
ADVISORYhttps://blog.clamav.net/2021/04/clamav-01032-security-patch-release.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/04/msg00012.html
ADVISORYhttps://security.gentoo.org/glsa/202104-07

All References (6)

→
https://blog.clamav.net/2021/04/clamav-01032-security-patch-release.htmlRelease Notes · Vendor Advisory
→
https://lists.debian.org/debian-lts-announce/2021/04/msg00012.htmlMailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202104-07Third Party Advisory
→
https://blog.clamav.net/2021/04/clamav-01032-security-patch-release.htmlRelease Notes · Vendor Advisory
→
https://lists.debian.org/debian-lts-announce/2021/04/msg00012.htmlMailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202104-07Third Party Advisory

Quick Facts

CVE IDCVE-2021-1405
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-120
CISA KEVNo
Affected2 vendor(s)
PublishedApr 8, 2021

Related CVEs (CWE-120)

CVE-1999-1237
10.0
CVE-2024-25139
10.0
CVE-2021-33972
10.0
CVE-2022-20827
10.0
CVE-2021-33975
10.0
CVE-1999-0385
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-1405 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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