CVE-2023-26041 Explained : Impact and Mitigation

This CVE involves Nextcloud Talk, a communication service, where messages can still be seen on a conversation even after expiring due to misconfigured cron jobs.

Understanding CVE-2023-26041

This vulnerability, tracked under CVE-2023-26041, highlights a security issue in Nextcloud Talk that allows expired messages to still be visible on conversations.

What is CVE-2023-26041?

The vulnerability in Nextcloud Talk arises when cron jobs are misconfigured, leading to messages not expiring as intended. As a result, the API continues to return these expired messages, even though they are hidden by the frontend code.

The Impact of CVE-2023-26041

This exposure of private personal information to unauthorized actors can have privacy implications for users relying on Nextcloud Talk for secure communication. The base severity of this vulnerability is rated as low, but the potential consequences of unauthorized access to private messages can still be concerning.

Technical Details of CVE-2023-26041

The vulnerability is classified with a CVSS v3.1 base score of 2.6 (Low severity) with the following details:

Attack Complexity: High
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Confidentiality Impact: Low
Integrity Impact: None
Availability Impact: None

Vulnerability Description

The misconfiguration of cron jobs in Nextcloud Talk leads to expired messages not being properly hidden and still being accessible via the API.

Affected Systems and Versions

Affected Vendor: Nextcloud
Affected Product: Nextcloud Talk
Affected Versions: Versions prior to 15.0.3 are impacted by this vulnerability.

Exploitation Mechanism

As the cron jobs are misconfigured, the messages that should have been expired are still accessible through the API, potentially exposing private conversations.

Mitigation and Prevention

Users and administrators are advised to take immediate steps to mitigate the risks posed by CVE-2023-26041.

Immediate Steps to Take

Upgrade Nextcloud Talk to version 15.0.3 as a critical measure to address this vulnerability.
Since there are no workarounds available, updating to the patched version is crucial to prevent unauthorized access to expired messages.

Long-Term Security Practices

Maintain regular software updates and security audits to detect and address vulnerabilities promptly, ensuring the security of communication systems.

Patching and Updates

Nextcloud users should regularly check for security advisories and apply updates promptly to mitigate potential risks associated with known vulnerabilities like CVE-2023-26041.