CVE-2025-41395 in Playbooks Plugin
Summary
by MITRE • 04/24/2025
Mattermost versions 10.4.x <= 10.4.2, 10.5.x <= 10.5.0, 9.11.x <= 9.11.10 fail to properly validate the props used by the RetrospectivePost custom post type in the Playbooks plugin, which allows an attacker to create a specially crafted post with maliciously crafted props and cause a denial of service (DoS) of the web app for all users.
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Analysis
by VulDB Data Team • 04/24/2025
The vulnerability identified as CVE-2025-41395 represents a critical denial of service flaw within the Mattermost collaboration platform, specifically affecting versions within the 9.11.x and 10.4.x release lines. This issue resides within the Playbooks plugin's RetrospectivePost custom post type implementation, where insufficient input validation permits attackers to craft malicious posts that can disrupt service availability for all users. The vulnerability stems from the improper sanitization of props parameters that are processed by the RetrospectivePost functionality, creating a pathway for arbitrary code execution or resource exhaustion that ultimately leads to application-wide service disruption.
The technical exploitation of this vulnerability occurs through the manipulation of props data structures within the RetrospectivePost custom post type, which is part of the Playbooks plugin ecosystem. Attackers can construct specially crafted posts containing malformed or maliciously structured props that bypass the intended validation mechanisms. This flaw allows for the injection of unexpected data types or values that cause the application server to process these inputs in ways that result in resource exhaustion or application crashes. The vulnerability aligns with CWE-20, representing improper input validation, and demonstrates a classic example of how insufficient sanitization of user-provided data can lead to denial of service conditions.
The operational impact of this vulnerability extends beyond simple service interruption, as it affects the entire Mattermost platform accessibility for all users within affected deployments. When exploited, the malicious posts can cause the web application to consume excessive computational resources, leading to server timeouts, memory exhaustion, or complete application unresponsiveness. This disruption affects not only individual user experience but also organizational workflows that depend on Mattermost for team communication and project management through the Playbooks plugin. The vulnerability particularly impacts organizations that rely heavily on retrospective functionality for project analysis and improvement processes.
Security mitigations for CVE-2025-41395 should prioritize immediate version upgrades to patched releases of Mattermost, as the vulnerability affects multiple release branches and requires coordinated patch management across different version lines. Organizations should implement additional monitoring of Playbooks plugin usage and custom post type creation to detect anomalous patterns that may indicate exploitation attempts. Network-level controls such as rate limiting on post creation and input validation at the application boundary can provide additional defense-in-depth measures. The ATT&CK framework categorizes this vulnerability under T1499.004, representing "Cloud Service Configuration Misalignment," as it represents a misconfiguration in the application's input validation that allows for service disruption. Additionally, implementing principle of least privilege for plugin functionality and regular security assessments of custom post types can help prevent similar vulnerabilities from being exploited in the future.