PatchSiren

PatchSiren cyber security CVE debrief

CVE-2016-8652 Dovecot CVE debrief

CVE-2016-8652 is a remote denial-of-service issue in Dovecot's auth component when auth-policy is configured. According to the supplied NVD record, an attacker can cause a crash by aborting authentication before a username is set. The affected version range is Dovecot versions before 2.2.27.

Vendor
Dovecot
Product
Unknown
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-17
Original CVE updated
2026-05-13
Advisory published
2017-02-17
Advisory updated
2026-05-13

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.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-8652 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-8652

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-8652 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-8652

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.