CVE-2021-34555

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer...

7.5 HighFix available

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

2.57%Up 1.6 points since Jun 11, 2021

What each source reports

NVD Score used 7.5

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: CVE-2021-34555
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-476
Updated: 2026-11-02

CVE List No score

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: CVE-2021-34555
Updated: 2026-11-02

EUVDEUVD-2021-21205 No score

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: EUVD-2021-21205
Updated: 2026-11-03

GitHub AdvisoriesGHSA-9774-4j5q-whvj No score

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer...

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: GHSA-9774-4j5q-whvj
Weakness: CWE-476
Updated: 2026-11-02

OSVALPINE-CVE-2021-34555 7.5

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: ALPINE-CVE-2021-34555
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

OSV 7.5

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: CVE-2021-34555
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-34555 7.5

OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a multi-value From header field.

Record: DEBIAN-CVE-2021-34555
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`opendmarc` Alpine:v3.14	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.15	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.16	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.17	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.18	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.19	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.20	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.21	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.22	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Alpine:v3.23	before 1.4.1.1-r3	1.4.1.1-r3

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Affected packages
Package	Affected	Fixed
`opendmarc` Alpine:v3.24	before 1.4.1.1-r3	1.4.1.1-r3
`opendmarc` Debian:12	before 1.4.0~beta1+dfsg-6	1.4.0~beta1+dfsg-6
`opendmarc` Debian:13	before 1.4.0~beta1+dfsg-6	1.4.0~beta1+dfsg-6
`opendmarc` Debian:14	before 1.4.0~beta1+dfsg-6	1.4.0~beta1+dfsg-6

History

History
Recorded	Changed	Sources
Nov 3, 2026	affected, aliases, references	OSV
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-34555 is a high vulnerability (CVSS 7.5) in Trusteddomain Opendmarc, published June 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.57%, the 85th percentile. Fixed in opendmarc 1.4.1.1-r3.

References

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