CVE-2023-28107 in Discourse
Summary
by MITRE • 03/17/2023
Discourse is an open-source discussion platform. Prior to version 3.0.2 of the `stable` branch and version 3.1.0.beta3 of the `beta` and `tests-passed` branches, a user logged as an administrator can request backups multiple times, which will eat up all the connections to the DB. If this is done on a site using multisite, then it can affect the whole cluster. The vulnerability is patched in version 3.0.2 of the `stable` branch and version 3.1.0.beta3 of the `beta` and `tests-passed` branches. There are no known workarounds.
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Analysis
by VulDB Data Team • 04/11/2023
The vulnerability identified as CVE-2023-28107 affects Discourse, an open-source discussion platform widely used for community forums and collaborative spaces. This security flaw resides in the backup functionality of the platform and specifically targets administrator accounts with elevated privileges. The issue manifests when administrators attempt to request multiple database backups simultaneously, creating a resource exhaustion scenario that can severely impact system availability and performance. The vulnerability exists across multiple release branches including the stable version prior to 3.0.2 and beta/test branches prior to 3.1.0.beta3, indicating a widespread impact within the platform's codebase. This represents a significant concern for organizations relying on Discourse for critical communication infrastructure where system uptime and reliability are paramount.
The technical flaw underlying CVE-2023-28107 constitutes a resource exhaustion attack pattern that leverages the backup request mechanism to consume all available database connections. When an administrator triggers multiple backup requests concurrently, the system fails to properly manage connection limits or implement rate limiting controls for backup operations. This creates a denial of service condition where legitimate database operations are blocked due to connection exhaustion, effectively preventing other users from accessing the platform's functionality. The vulnerability is particularly dangerous in multisite deployments where the impact extends beyond individual sites to affect the entire cluster infrastructure, demonstrating how a single flaw can cascade across interconnected systems. This behavior aligns with CWE-400 vulnerability classification for unrestricted resource consumption, where the system lacks proper safeguards against excessive resource utilization by authenticated users.
The operational impact of this vulnerability extends far beyond simple performance degradation to encompass complete system unavailability and potential data access disruptions. In multisite configurations, an attacker with administrative credentials can effectively take down entire clusters of Discourse installations, impacting multiple organizations or communities simultaneously. The consequences include service interruption for legitimate users, potential data loss scenarios during backup operations, and increased administrative overhead for system recovery. Organizations using Discourse in production environments face significant risk of operational disruption, particularly in mission-critical applications where continuous availability is required. The vulnerability also creates opportunities for attackers to exploit system resources for further malicious activities, potentially leading to more severe security incidents within the broader infrastructure ecosystem.
Mitigation strategies for CVE-2023-28107 require immediate deployment of patched versions as specified in the advisory. Organizations must prioritize upgrading their Discourse installations to version 3.0.2 for stable releases or 3.1.0.beta3 for beta and tests-passed branches to eliminate the vulnerability. While no specific workarounds are documented, system administrators should implement additional monitoring and access controls to detect unusual backup request patterns that might indicate exploitation attempts. The patch addresses the root cause by implementing proper connection management and rate limiting for backup operations, preventing the exhaustion of database connections through multiple simultaneous requests. Security teams should conduct thorough vulnerability assessments of their Discourse installations to ensure complete remediation and monitor for any related suspicious activities that might indicate attempted exploitation of similar vulnerabilities within their infrastructure. This vulnerability highlights the importance of proper resource management and access control in web applications, particularly those handling sensitive user data and community interactions.