CVE-2020-10958Network attack vector

Unauthenticated service crash via freed command memory

Published May 18, 2020 · Updated Aug 4, 2024

Use-after-free in Dovecot 2.3.0 through 2.3.10 allows remote attackers to crash submission, submission-login, or LMTP services. After 10 to 20 invalid or unknown commands, the service closes the connection with a 421 error but accesses command memory that it has already freed. Submission-login is reachable without authentication and repeated triggers can keep it unavailable; LMTP is normally restricted behind a trusted MTA.

CVSS severity5.3
Medium
EPSS probability6.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Dovecot 2.3.0 through 2.3.10 allows remote attackers to crash submission, submission-login, or LMTP services. After 10 to 20 invalid or unknown commands, the service closes the connection with a 421 error but accesses command memory that it has already freed. Submission-login is reachable without authentication and repeated triggers can keep it unavailable; LMTP is normally restricted behind a trusted MTA.

The record

CVE
CVE-2020-10958
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

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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

5.3OX Software GmbHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

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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 exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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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