Dovecot up to 2.2.28 dict Authentication var_expand input validation

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Dovecot up to 2.2.28. It has been declared as problematic. Impacted is the function var_expand of the component dict Authentication. Such manipulation leads to input validation. This vulnerability is uniquely identified as CVE-2017-2669. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Dovecot up to 2.2.28 (Mail Server Software). It has been rated as problematic. Affected by this issue is the function var_expand of the component dict Authentication. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is availability. CVE summarizes:

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.

The bug was discovered 04/11/2017. The weakness was disclosed 06/21/2018 (Website). The advisory is available at dovecot.org. This vulnerability is handled as CVE-2017-2669 since 12/01/2016. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 99279 (Ubuntu 16.04 LTS / 16.10 : dovecot vulnerability (USN-3258-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 170186 (OpenSUSE Security Update for dovecot22 (openSUSE-SU-2017:1807-1)).

Upgrading to version 2.2.29 eliminates this vulnerability. A possible mitigation has been published before and not just after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (99279) and SecurityFocus (BID 97536†). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CNA Base Score: 3.7
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 99279
Nessus Name: Ubuntu 16.04 LTS / 16.10 : dovecot vulnerability (USN-3258-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for dovecot FEDORA-2017-da4ed58fd5
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Dovecot 2.2.29
Patch: github.com

Timelineinfo

12/01/2016 🔍
04/10/2017 +130 days 🔍
04/10/2017 +0 days 🔍
04/11/2017 +1 days 🔍
04/11/2017 +0 days 🔍
06/21/2018 +435 days 🔍
06/21/2018 +0 days 🔍
06/21/2018 +0 days 🔍
03/28/2023 +1741 days 🔍

Sourcesinfo

Advisory: USN-3258-1
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-2669 (🔍)
GCVE (CVE): GCVE-0-2017-2669
GCVE (VulDB): GCVE-100-119762

OVAL: 🔍

SecurityFocus: 97536 - Dovecot CVE-2017-2669 Denial of Service Vulnerability

Entryinfo

Created: 06/21/2018 19:04
Updated: 03/28/2023 13:02
Changes: 06/21/2018 19:04 (76), 02/20/2020 21:36 (3), 03/28/2023 12:47 (5), 03/28/2023 12:55 (12), 03/28/2023 13:02 (1)
Complete: 🔍
Cache ID: 216::103

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