CVE-2019-10691 Explained : Impact and Mitigation

Dovecot before version 2.3.5.2 is vulnerable to repeated crashes in the authentication service due to invalid UTF-8 sequences in the username.

Understanding CVE-2019-10691

This CVE involves a vulnerability in Dovecot that allows attackers to cause repeated crashes in the authentication service by using an invalid UTF-8 sequence as the username.

What is CVE-2019-10691?

The JSON encoder in Dovecot before version 2.3.5.2 enables attackers to crash the authentication service by attempting to authenticate with an invalid UTF-8 sequence as the username.

The Impact of CVE-2019-10691

This vulnerability can be exploited by attackers to disrupt the authentication service of Dovecot, potentially leading to denial of service (DoS) conditions.

Technical Details of CVE-2019-10691

Dovecot CVE-2019-10691 involves the following technical aspects:

Vulnerability Description

Attackers can cause repeated crashes in the authentication service of Dovecot by using an invalid UTF-8 sequence as the username.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: Dovecot versions prior to 2.3.5.2

Exploitation Mechanism

The vulnerability is exploited by making authentication attempts using an invalid UTF-8 sequence as the username in Dovecot.

Mitigation and Prevention

To address CVE-2019-10691, consider the following mitigation strategies:

Immediate Steps to Take

Upgrade Dovecot to version 2.3.5.2 or later to mitigate the vulnerability.
Monitor for any unusual authentication attempts or crashes in the authentication service.

Long-Term Security Practices

Regularly update and patch Dovecot to ensure the latest security fixes are applied.
Implement strong authentication mechanisms to prevent unauthorized access.

Patching and Updates

Apply patches provided by Dovecot promptly to address security vulnerabilities and improve system resilience.