CVE-2020-10967Public exploitNetwork attack vector

Mail-delivery denial of service via empty quoted local-part

Published May 18, 2020 · Updated Aug 4, 2024

Improper input validation in Dovecot 2.3.0 through 2.3.10 allows remote attackers to crash LMTP or submission mail delivery. The submission and LMTP address-handling path fails to reject an empty quoted local-part in an envelope sender or recipient before processing it, terminating the service process. Submission requires valid credentials; LMTP exposure depends on a trusted MTA forwarding the crafted address, and repeated messages can interrupt mail delivery.

CVSS severity5.3
Medium
EPSS probability8.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Dovecot 2.3.0 through 2.3.10 allows remote attackers to crash LMTP or submission mail delivery. The submission and LMTP address-handling path fails to reject an empty quoted local-part in an envelope sender or recipient before processing it, terminating the service process. Submission requires valid credentials; LMTP exposure depends on a trusted MTA forwarding the crafted address, and repeated messages can interrupt mail delivery.

The record

CVE
CVE-2020-10967
Published
May 18, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 18, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

5.3MITRECVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.3OX Software GmbHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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-20Improper Input Validation
T1499.004Application or System Exploitation

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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