Opendmarc
CVE-2021-34555
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could crash the application by dereferencing a null pointer by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
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. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.
Affects your stack
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Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a 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. Affected products include: Trusteddomain Opendmarc, Fedoraproject Fedora.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
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.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)NVD
OpenDMARC through 1.3.2 and 1.4.x through 1.4.0-Beta1 has improper null termination in the function opendmarc_xml_parse
OpenDMARC 1.4.2 contains a null pointer dereference vulnerability in /OpenDMARC/libopendmarc/opendmarc_policy.c. Rated h
OpenDMARC through 1.3.2 and 1.4.x through 1.4.0-Beta1 is prone to a signature-bypass vulnerability with multiple From: a
Email authentication bypass in OpenDMARC up to 1.4.2 allows remote unauthenticated attackers to spoof sender domains by
DMARC authentication bypass in Trusted Domain Project OpenDMARC through 1.4.2 lets a remote attacker defeat the DMARC an
Integer overflow in OpenDMARC through 1.4.2 allows unauthenticated remote attackers to corrupt DMARC policy-percentage h
DMARC policy evaluation in Trusted Domain Project OpenDMARC through 1.4.2 can be bypassed by mail carrying sending-domai
OpenDMARC through 1.4.2 can mishandle Internationalized Domain Name labels during DMARC policy lookup in opendmarc_polic
Malformed DMARC policy tags (fo, rf, ri, pct, sp, adkim, aspf, rua, ruf) supplied in attacker-controlled DNS TXT records
Off-by-one bounds error in Trusted Domain Project OpenDMARC through 1.4.2 lets a remote, unauthenticated attacker send a
A NULL pointer dereference in the Trusted Domain Project's OpenDMARC (up to and including 1.4.2) can crash the mail filt
OpenDMARC through 1.3.2 and 1.4.x allows attacks that inject authentication results to provide false information about t
Exploit-DB