CVE-2022-35932 in Talk
Summary
by MITRE • 08/12/2022
Nextcloud Talk is a video and audio conferencing app for Nextcloud. Prior to versions 12.2.7, 13.0.7, and 14.0.3, password protected conversations are susceptible to brute force attacks if the attacker has the link/conversation token. It is recommended that the Nextcloud Talk application is upgraded to 12.2.7, 13.0.7 or 14.0.3. There are currently no known workarounds available apart from not having password protected conversations.
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Analysis
by VulDB Data Team • 08/12/2022
The vulnerability described in CVE-2022-35932 represents a critical security weakness in Nextcloud Talk's password protection mechanism that exposes users to brute force attacks. This issue affects versions prior to 12.2.7, 13.0.7, and 14.0.3 of the Nextcloud Talk application, which is a video and audio conferencing solution integrated into the Nextcloud platform. The flaw specifically targets password-protected conversations, creating a scenario where unauthorized attackers can systematically attempt to guess valid passwords through automated means. The vulnerability's severity is amplified by the fact that attackers only need access to the conversation link or token to initiate these brute force attempts, eliminating the need for additional reconnaissance or privilege escalation.
The technical implementation flaw lies in the insufficient rate limiting and authentication mechanisms within the password validation process. When users create password-protected conversations, the system should enforce strict controls to prevent rapid successive authentication attempts that characterize brute force attacks. However, prior to the patched versions, the application failed to adequately implement protective measures such as account lockout mechanisms, exponential backoff delays, or maximum attempt thresholds. This allows attackers to make numerous password guesses in quick succession, significantly increasing their chances of successfully compromising the conversation. The vulnerability directly relates to CWE-307, which addresses inadequate protection against brute force attacks, and represents a failure in implementing proper authentication controls.
The operational impact of this vulnerability extends beyond individual conversations to potentially compromise entire Nextcloud deployments. Organizations relying on Nextcloud Talk for sensitive communications face significant risks when attackers exploit this weakness, particularly in environments where password-protected meetings are frequently used for business-critical discussions, healthcare consultations, or educational sessions. The attack surface is further expanded because the vulnerability can be exploited without requiring elevated privileges or complex attack vectors, making it accessible to adversaries with minimal technical expertise. From an attacker's perspective, this represents a low-hanging fruit vulnerability that can be automated using readily available tools, potentially leading to unauthorized access to confidential information shared during protected conversations.
Security practitioners should prioritize upgrading affected Nextcloud Talk installations to versions 12.2.7, 13.0.7, or 14.0.3 as the primary remediation measure. The patch implementations likely include enhanced authentication controls, rate limiting mechanisms, and improved session management to prevent the conditions that enabled brute force attacks. While the vulnerability description indicates no known workarounds exist, organizations should consider implementing additional protective measures such as network-level restrictions, monitoring for suspicious authentication patterns, and regular security audits of their Nextcloud deployments. The ATT&CK framework categorizes this vulnerability under credential access techniques, specifically targeting the use of brute force methods to obtain unauthorized access to protected resources. Organizations should also consider implementing multi-factor authentication for critical Nextcloud accounts and establishing monitoring protocols to detect unusual authentication patterns that might indicate brute force activity.
The broader implications of this vulnerability highlight the importance of maintaining current security practices in collaborative platforms, particularly those handling sensitive communications. This issue demonstrates how seemingly minor implementation flaws in authentication systems can create significant security risks when combined with the accessibility of modern web-based applications. The vulnerability serves as a reminder of the critical need for robust authentication controls, proper rate limiting, and regular security updates in enterprise collaboration tools that handle confidential information. Organizations should conduct thorough assessments of their Nextcloud deployments to identify all affected components and ensure complete remediation through proper version upgrades and configuration reviews.