CVE-2021-32689 : Exploit Details and Defense Strategies
Learn about CVE-2021-32689, a high-severity vulnerability in Nextcloud Talk allowing unauthorized access to chat messages. Mitigation steps included. Upgrade to versions 11.2.2 or 11.3.0 for security.
Nextcloud Talk is a fully on-premises audio/video and chat communication service. In versions prior to 11.2.2, a vulnerability allowed users to access any chat message sent to a previous user with the same username. The issue was resolved in versions 11.2.2 and 11.3.0. To mitigate, ensure users cannot choose usernames.
Understanding CVE-2021-32689
In this CVE, Nextcloud Talk failed to properly disassociate users from chats after account deletion.
What is CVE-2021-32689?
CVE-2021-32689 highlights a security flaw in Nextcloud Talk versions earlier than 11.2.2 that enabled users to access chat messages intended for previous users with the same username.
The Impact of CVE-2021-32689
The vulnerability posed a high severity risk with a CVSS base score of 8.1, impacting confidentiality and integrity.
Technical Details of CVE-2021-32689
The technical details of the CVE include:
Vulnerability Description
The flaw allowed users to access chat messages of previous users with the same username.
Affected Systems and Versions
Nextcloud Talk versions prior to 11.2.2 were affected by this vulnerability.
Exploitation Mechanism
By reusing an existing username, users could gain unauthorized access to chat messages.
Mitigation and Prevention
To address CVE-2021-32689, follow these steps:
Immediate Steps to Take
Ensure users cannot choose their usernames to prevent unauthorized access to chat messages.
Long-Term Security Practices
Regularly update Nextcloud Talk to the latest versions to avoid security vulnerabilities.
Patching and Updates
Upgrade to Nextcloud Talk versions 11.2.2 or 11.3.0 to eliminate the risk associated with this vulnerability.