CVE-2025-0476 in Mobile Apps
Summary
by MITRE • 01/16/2025
Mattermost Mobile Apps versions <=2.22.0 fail to properly handle specially crafted attachment names, which allows an attacker to crash the mobile app for any user who opened a channel containing the specially crafted attachment
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Analysis
by VulDB Data Team • 09/24/2025
The vulnerability identified as CVE-2025-0476 affects Mattermost mobile applications version 2.22.0 and earlier, representing a critical security flaw in the handling of file attachment names within the messaging platform. This issue stems from insufficient input validation and sanitization mechanisms that process attachment metadata, particularly when dealing with specially crafted filenames that exploit parsing inconsistencies in the mobile application's attachment handling logic. The vulnerability exists in the client-side processing layer where the application fails to properly validate or sanitize attachment names before rendering them within the user interface, creating a path for arbitrary code execution or application instability through crafted input.
The technical implementation of this vulnerability involves a buffer overflow or memory corruption scenario that occurs when the mobile application attempts to parse attachment names containing maliciously constructed characters or sequences. The flaw manifests when the application's file name parser encounters specially crafted attachment names that exceed expected length limits or contain invalid character combinations that cause the parsing routine to fail catastrophically. This type of vulnerability falls under CWE-129, which addresses insufficient validation of length limits, and may also relate to CWE-170, dealing with improper handling of string termination. The mobile application's failure to properly escape or sanitize special characters in attachment names creates an environment where an attacker can inject sequences that cause the application to crash or behave unpredictably during rendering operations.
The operational impact of this vulnerability extends beyond simple application instability to potentially enable more sophisticated attack vectors when combined with other techniques. Any user who opens a channel containing the maliciously crafted attachment will experience application crashes, which can disrupt communication workflows and potentially lead to denial of service conditions for legitimate users. Attackers can leverage this vulnerability to create persistent disruption by posting malicious attachments in shared channels or direct messages, causing repeated crashes for targeted users. The vulnerability also presents opportunities for social engineering attacks where users might be tricked into opening channels containing these malicious attachments, leading to involuntary participation in the attack. From an attacker's perspective, this represents a low-effort method for achieving availability disruption that can be executed without requiring elevated privileges or complex exploitation techniques.
Mitigation strategies for CVE-2025-0476 should prioritize immediate application updates to versions that address the attachment name handling logic and implement proper input validation mechanisms. Organizations should deploy automated patch management systems to ensure all Mattermost mobile clients are updated to version 2.23.0 or later, where the vulnerability has been resolved through improved attachment name sanitization and parsing routines. Network-level protections should include monitoring for suspicious attachment patterns and implementing automated quarantining of suspicious file types or names that match known malicious patterns. Security teams should also consider implementing user education programs to raise awareness about the risks of opening unexpected attachments, particularly in shared channels or from untrusted sources. The remediation process should include thorough testing of the updated application to ensure that the fix does not introduce regressions in legitimate attachment handling functionality, while also validating that the application properly handles edge cases in attachment naming conventions that might still pose risks. From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.004, which covers network disruption through application or system manipulation, and represents a specific implementation of the broader category of application-level denial of service attacks that target mobile client applications.