CVE-2025-1691 in mongosh
Summary
by MITRE • 02/27/2025
The MongoDB Shell may be susceptible to control character injection where an attacker with control of the mongosh autocomplete feature, can use the autocompletion feature to input and run obfuscated malicious text. This requires user interaction in the form of the user using ‘tab’ to autocomplete text that is a prefix of the attacker’s prepared autocompletion. This issue affects mongosh versions prior to 2.3.9.
The vulnerability is exploitable only when mongosh is connected to a cluster that is partially or fully controlled by an attacker.
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Analysis
by VulDB Data Team • 09/22/2025
The vulnerability identified as CVE-2025-1691 represents a sophisticated control character injection flaw within the MongoDB Shell (mongosh) environment. This security weakness specifically targets the autocompletion functionality that users rely upon for efficient database interaction. The flaw manifests when an attacker gains partial or complete control over a MongoDB cluster and can manipulate the autocompletion suggestions provided by the mongosh interface. The vulnerability falls under the category of CWE-74, which describes improper neutralization of special elements employed in a command or query, making it particularly dangerous in database administration contexts where command execution is frequent.
The technical exploitation of this vulnerability requires a specific set of conditions that must align for successful attack execution. An attacker must first establish control over the MongoDB cluster being accessed through mongosh, either partially or fully, to inject malicious autocompletion entries. The attack vector specifically relies on user interaction where the victim must actively engage the tab key to trigger the autocompletion feature. When the user presses tab, the maliciously crafted autocompletion text becomes embedded in the shell environment and can execute obfuscated commands. This type of vulnerability demonstrates the inherent risks of interactive shell environments where user input is processed without adequate sanitization of completion suggestions, creating a pathway for command injection through seemingly benign autocompletion features.
The operational impact of CVE-2025-1691 extends beyond simple command execution, potentially enabling attackers to escalate privileges and access sensitive database information. Since the vulnerability requires user interaction, it represents a form of social engineering that combines technical exploitation with human factors, making it particularly challenging to defend against. The attack scenario assumes that the attacker has already established a foothold within the MongoDB cluster, which means that this vulnerability serves as an escalation vector rather than an initial access point. The obfuscated nature of the malicious text in the autocompletion suggestions makes detection difficult for security monitoring systems that may not recognize the subtle command injection patterns. This vulnerability directly aligns with ATT&CK technique T1059.006 for command and script injection, as it enables attackers to execute arbitrary commands through the shell interface.
Mitigation strategies for this vulnerability must address both the immediate software patching requirements and broader security practices for shell environments. The primary solution involves upgrading mongosh to version 2.3.9 or later, which contains the necessary fixes to prevent control character injection through autocompletion features. Organizations should implement comprehensive patch management procedures to ensure all MongoDB shell installations receive timely updates. Additionally, security teams should consider implementing monitoring for suspicious autocompletion patterns and user behavior anomalies that might indicate exploitation attempts. The vulnerability highlights the importance of input validation in interactive environments and reinforces the principle that all user-provided data, including autocompletion suggestions, must be properly sanitized before processing. Network segmentation and access control measures should also be strengthened to limit the potential impact of cluster compromise, as the vulnerability's exploitation requires attacker control over the target cluster environment.