CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
Lifecycle Timeline
4Description
Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.
Analysis
OX Dovecot Pro SQL-based authentication can be completely bypassed when administrators clear the auth_username_chars configuration parameter, enabling unauthenticated attackers to authenticate as any user and enumerate valid usernames. Open-Xchange GmbH OX Dovecot Pro is affected, with CVSS 7.7 (High) severity and attack complexity High. …
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Remediation
Within 24 hours: audit all OX Dovecot Pro instances to identify deployments where auth_username_chars configuration parameter has been cleared or set to non-default values; document findings and isolate affected systems from user-facing access if possible. Within 7 days: implement network segmentation to restrict direct access to Dovecot authentication ports; enable detailed logging for all authentication attempts; coordinate with Open-Xchange GmbH for configuration hardening guidance. …
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Priority Score
Vendor Status
Ubuntu
Priority: Medium| Release | Status | Version |
|---|---|---|
| trusty | not-affected | code not present |
| xenial | not-affected | code not present |
| bionic | not-affected | code not present |
| focal | not-affected | code not present |
| jammy | not-affected | code not present |
| noble | not-affected | code not present |
| questing | needed | - |
| upstream | released | 2.4.3 |
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | vulnerable | 1:2.3.13+dfsg1-2+deb11u1 | - |
| bullseye (security) | vulnerable | 1:2.3.13+dfsg1-2+deb11u2 | - |
| bookworm, bookworm (security) | vulnerable | 1:2.3.19.1+dfsg1-2.1+deb12u1 | - |
| trixie | vulnerable | 1:2.4.1+dfsg1-6+deb13u3 | - |
| trixie (security) | vulnerable | 1:2.4.1+dfsg1-6+deb13u1 | - |
| forky, sid | vulnerable | 1:2.4.2+dfsg1-4 | - |
| (unstable) | fixed | (unfixed) | - |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-16561
GHSA-fx6f-5qgf-9fmx