CVE-2023-45806 Explained : Impact and Mitigation

Discourse is an open source platform for community discussion. A vulnerability in Discourse prior to versions 3.1.3 and 3.2.0.beta3 allows for Denial of Service (DoS) attacks via Regexp Injection in the Full Name field. The issue arises when a user quoted in a discussion uses a

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character in their full name, leading to the generation of duplicate content in all posts they've been quoted in by updating their full name again. The impact is moderate with a CVSS base score of 4.3.

Understanding CVE-2023-45806

This vulnerability, identified as CWE-1333, involves inefficient regular expression complexity in Discourse, enabling attackers to exploit the Full Name field to trigger a DoS condition.

What is CVE-2023-45806?

CVE-2023-45806 pertains to a security flaw in Discourse versions below 3.1.3 and 3.2.0.beta3, allowing for DoS attacks through Regexp Injection in the Full Name attribute.

The Impact of CVE-2023-45806

The vulnerability poses a moderate risk, with a CVSS base score of 4.3. Exploitation may lead to the generation of excessive duplicate content in quoted posts, impacting system availability.

Technical Details of CVE-2023-45806

The vulnerability description, affected systems, and exploitation mechanism of CVE-2023-45806 are as follows:

Vulnerability Description

The security issue stems from the Full Name field in Discourse, where the presence of a

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character in a quoted user's name can trigger a bug, resulting in the duplication of content across all related posts.

Affected Systems and Versions

Versions prior to 3.1.3 in the stable branch and 3.2.0.beta3 in the beta and tests-passed branches of Discourse are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit the vulnerability by quoting a user with a

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in their full name and subsequently updating the name, causing excessive duplicate content in all posts where the user has been quoted.

Mitigation and Prevention

To mitigate the risks associated with CVE-2023-45806, users and administrators can take the following steps:

Immediate Steps to Take

Update Discourse to version 3.1.3 in the stable branch or version 3.2.0.beta3 in the beta and tests-passed branches to apply the necessary patch.

Long-Term Security Practices

Encourage users to avoid special characters like

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in their full names to prevent triggering the vulnerability.

Patching and Updates

Regularly monitor and apply security patches and updates provided by Discourse to safeguard systems against known vulnerabilities.