CVE-2016-8652 Dovecot CVE debrief

Who should care

Mail system administrators, platform engineers, and security teams operating Dovecot with auth-policy enabled should review this issue, especially on Internet-facing authentication services.

Technical summary

The vulnerability is a network-reachable availability issue in Dovecot auth handling. NVD classifies it as CWE-20 and assigns CVSS 3.0 vector CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H. The supplied record states the issue occurs when auth-policy is configured and authentication is aborted without a username, leading to a crash. The affected CPE range in the corpus ends at Dovecot 2.2.27.

Defensive priority

Medium. This is not a confidentiality or integrity issue, but it is remotely reachable and can crash authentication services when the vulnerable configuration is present.

Recommended defensive actions

• Confirm whether any Dovecot deployments use auth-policy and whether they are running a version earlier than 2.2.27.
• Upgrade affected Dovecot instances to version 2.2.27 or later.
• Review authentication failure and crash logs for signs of repeated auth-service restarts or unexpected terminations.
• If immediate upgrade is not possible, reduce exposure of the affected authentication service and monitor it closely until remediation is complete.

Evidence notes

The debrief is based on the supplied CVE description and NVD metadata. The record identifies Dovecot as affected, with a vulnerable version range ending at 2.2.27, a CWE-20 weakness classification, and a CVSS 3.0 vector indicating network-reachable availability impact only. Supplied references include a vendor release note/advisory, OSS-security mailing list posts, and a SecurityFocus entry.

Official resources