Vulnerability Monitor

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CVE-2017-2669

Dovecot before version 2.2.29 is vulnerable to a denial of service. When 'dict' passdb and userdb were used for user authentication, the username sent by the IMAP/POP3 client was sent through var_expand() to perform %variable expansion. Sending specially crafted %variable fields could result in excessive memory usage causing the process to crash (and restart), or excessive CPU usage causing all authentications to hang.

Security Impact Summary

This vulnerability carries a LOW severity rating with a CVSS v3.1 score of 3.7, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and limited availability for affected systems. Impacting 2 products from dovecot, from debian organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2018, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.

Published

2018-06-21T13:29:00.317

Last Modified

2026-06-17T01:16:37.520

Status

Modified

Source

[email protected]

Severity

CVSSv3.0: 3.7 (LOW)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

Access Vector: NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: PARTIAL

Exploitability Score

10.0

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-20
Type: Primary
CWE-20

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	dovecot	dovecot	≤ 2.2.28	Yes
Operating System	debian	debian_linux	8.0	Yes

References

http://www.openwall.com/lists/oss-security/2017/04/11/1 Mailing List, Third Party Advisory ([email protected])
http://www.securityfocus.com/bid/97536 Third Party Advisory, VDB Entry ([email protected])
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2669 Issue Tracking, Third Party Advisory ([email protected])
https://dovecot.org/pipermail/dovecot-news/2017-April/000341.html Vendor Advisory ([email protected])
https://github.com/dovecot/core/commit/000030feb7a30f193197f1aab8a7b04a26b42735.patch Third Party Advisory ([email protected])
https://www.debian.org/security/2017/dsa-3828 Third Party Advisory ([email protected])
http://www.openwall.com/lists/oss-security/2017/04/11/1 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://www.securityfocus.com/bid/97536 Third Party Advisory, VDB Entry (af854a3a-2127-422b-91ae-364da2661108)
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2669 Issue Tracking, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://dovecot.org/pipermail/dovecot-news/2017-April/000341.html Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/dovecot/core/commit/000030feb7a30f193197f1aab8a7b04a26b42735.patch Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.debian.org/security/2017/dsa-3828 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For dovecot's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.