CVE-2020-12272Public exploitNetwork attack vector

Sender spoofing via malformed authentication-result domains

Published Apr 27, 2020 · Updated Aug 4, 2024

Authentication-results injection in OpenDMARC before 1.4.1 allows remote attackers to spoof a message's authenticated sender domain. The opendmarc_policy_store_spf and opendmarc_policy_store_dkim paths accept malformed domain values containing comment or quote characters, so SPF or DKIM verifies an attacker-controlled domain while DMARC aligns a truncated trusted domain. A target mail server must combine OpenDMARC with an SPF or DKIM component that forwards the crafted Authentication-Results value; successful messages receive false SPF, DKIM, or DMARC pass results.

CVSS severity5.3
Medium
EPSS probability2.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication-results injection in OpenDMARC before 1.4.1 allows remote attackers to spoof a message's authenticated sender domain. The opendmarc_policy_store_spf and opendmarc_policy_store_dkim paths accept malformed domain values containing comment or quote characters, so SPF or DKIM verifies an attacker-controlled domain while DMARC aligns a truncated trusted domain. A target mail server must combine OpenDMARC with an SPF or DKIM component that forwards the crafted Authentication-Results value; successful messages receive false SPF, DKIM, or DMARC pass results.

The record

CVE
CVE-2020-12272
Published
Apr 27, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-290, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 27, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
T1036Masquerading

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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