CVE-2024-3872 in Mattermost
Summary
by MITRE • 04/16/2024
Mattermost Mobile app versions 2.13.0 and earlier use a regular expression with polynomial complexity to parse certain deeplinks, which allows an unauthenticated remote attacker to freeze or crash the app via a long maliciously crafted link.
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Analysis
by VulDB Data Team • 04/06/2025
The vulnerability identified as CVE-2024-3872 represents a critical denial-of-service weakness in the Mattermost mobile application ecosystem affecting versions 2.13.0 and earlier. This flaw stems from the application's improper handling of deep links through the use of regular expressions that exhibit polynomial time complexity during pattern matching operations. The vulnerability specifically targets the mobile application's parsing mechanism for deep links, which are URLs designed to open specific content within the application rather than launching a web browser. When an attacker crafts a maliciously long deep link that exploits the vulnerable regular expression, the application's processing time increases exponentially, leading to complete application freezing or crash conditions.
The technical implementation of this vulnerability involves the application's reliance on regular expressions with exponential time complexity for deep link parsing operations. This design choice creates a path for attackers to exploit the computational overhead inherent in certain regex patterns, particularly those containing nested quantifiers or backtracking mechanisms. The vulnerability manifests when the mobile application attempts to process a crafted deep link that triggers the regular expression engine to perform an excessive number of operations, effectively consuming all available processing resources. This behavior aligns with CWE-1333, which describes weaknesses related to regular expression denial of service attacks where poorly constructed regular expressions can be exploited to cause excessive computational resource consumption.
From an operational perspective, this vulnerability presents a significant risk to Mattermost mobile application users and organizations relying on the platform for communication. The attack requires no authentication or user interaction beyond clicking a malicious link, making it particularly dangerous in environments where users may encounter untrusted content through email, messaging platforms, or social media. The impact extends beyond simple application instability, potentially disrupting critical business communications and collaboration workflows. Organizations using Mattermost for enterprise communication may face service interruptions, reduced productivity, and potential security concerns if attackers systematically exploit this vulnerability to target mobile endpoints.
The exploitation of CVE-2024-3872 aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and denial of service operations. While the vulnerability does not directly enable code execution or data theft, it provides an entry point for attackers to degrade service availability and potentially pave the way for more sophisticated attacks. Security professionals should consider this vulnerability as part of a broader threat landscape where mobile application stability and resource management are critical components of overall security posture. Organizations should implement immediate mitigations including updating to patched versions of the Mattermost mobile application, implementing network-level controls to filter suspicious deep links, and establishing monitoring procedures to detect potential exploitation attempts.
The remediation approach for this vulnerability requires immediate deployment of patched mobile application versions that address the regular expression complexity issue. Security teams should also consider implementing input validation controls that limit the length and complexity of deep link parameters processed by the application. Additionally, organizations may need to establish application whitelisting policies that restrict which deep links are processed by the mobile client, thereby reducing the attack surface for this specific vulnerability. The incident highlights the importance of regular security assessments of mobile application components and the need for robust input validation mechanisms that can withstand adversarial testing and exploitation attempts.