CVE-2023-23624 : Exploit Details and Defense Strategies

Discourse's exclude_tags param could leak which topics had a specific hidden tag.

Understanding CVE-2023-23624

Discourse, an open-source discussion platform, was found to have a vulnerability prior to version 3.0.1 on the

stable

branch and version 3.1.0.beta2 on the

beta

and

tests-passed

branches. This vulnerability allowed an unauthorized actor to use the

exclude_tag param

to filter out topics, potentially deducing which topics were using a specific hidden tag. This issue could impact any Discourse site utilizing hidden tags in public categories.

What is CVE-2023-23624?

The vulnerability in Discourse, tracked as CVE-2023-23624, falls under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor. It has been assigned a CVSSv3 base score of 4.3, categorizing it as a medium severity issue.

The Impact of CVE-2023-23624

The impact of CVE-2023-23624 includes potential exposure of sensitive information to unauthorized actors. By utilizing the exclude_tags param, attackers could discern topics associated with hidden tags, compromising the confidentiality of data on affected Discourse sites.

Technical Details of CVE-2023-23624

The vulnerability description, affected systems, and exploitation mechanism of CVE-2023-23624 are crucial to understanding the risk and impact associated with this security issue.

Vulnerability Description

Prior to version 3.0.1 on the

stable

branch and version 3.1.0.beta2 on the

beta

and

tests-passed

branches of Discourse, the exclude_tags param allowed for the filtering out of topics, potentially revealing those using specific hidden tags. This flaw could lead to the exposure of sensitive information on Discourse sites.

Affected Systems and Versions

The vulnerability affects Discourse versions less than 3.0.1 on the

stable

branch and version 3.1.0.beta1 on the

beta

branch. Sites utilizing hidden tags in public categories are at risk of exploitation.

Exploitation Mechanism

Attackers with low privileges could exploit this vulnerability remotely over a network without requiring user interaction. The attack complexity is low, with no impact on integrity or availability but poses a risk to confidentiality.

Mitigation and Prevention

Addressing CVE-2023-23624 requires immediate actions to secure affected Discourse sites and prevent potential exploitation.

Immediate Steps to Take

Site administrators should apply the necessary patches released in version 3.0.1 on the

stable

branch and version 3.1.0.beta2 on the

beta

and

tests-passed

branches. Secure any categories utilizing hidden tags, modify existing hidden tags to exclude private data, and remove any hidden tags that may lead to data exposure.

Long-Term Security Practices

In the long term, organizations should implement a robust security posture by regularly updating software, monitoring for security advisories, and following best practices for data protection to prevent similar vulnerabilities.

Patching and Updates

Regularly check for security updates from Discourse and promptly apply patches to ensure the security of your systems. Stay informed about security advisories and take necessary actions to mitigate risks associated with known vulnerabilities.