Threat landscape
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Dovecot: Mehrere Schwachstellen ermöglichen Denial of Service

WID-SEC-2025-0235 · first 13.08.2020 · updated 11.08.2026 · CVSS 7,5

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What it is about

Dovecot ist ein Open Source IMAP und POP3 E-Mail Server. Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Dovecot, ausnutzen, um einen Denial of Service Angriff durchzuführen.

Under what conditions?

Over the network and without logging in. This is the most dangerous combination: attackers can scan reachable devices automatically.

What can happen in the worst case

An attacker could use the vulnerability to

  • einen Denial of Service Angriff durchzuführen

Am I affected?

Affected according to the BSI:

  • Open Source CentOS
  • Debian Linux
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Gentoo Linux
  • Open Source Dovecot <2.3.11.3
  • SUSE openSUSE
  • Oracle Linux

The installed version is usually shown under “Help → About” or in the device’s admin interface.

What helps?

Update to at least:

  • Open Source Dovecot 2.3.11.3

Is the vulnerability already being exploited?

None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.

Information and sources

CVE: CVE-2020-12100, CVE-2020-12673, CVE-2020-12674

Source: BSI warning and information service (CERT-Bund); CISA. The assessment of the conditions is my reading of the BSI text; the external pages are in their original language.

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