CVE-2025-6514 is a critical OS command injection vulnerability identified in version 0.0.5 of the mcp-remote software. The vulnerability arises due to improper neutralization of special elements in the input received from the authorization_endpoint response URL when connecting to untrusted MCP servers. Specifically, the application fails to sanitize or validate this crafted input properly, allowing an attacker to inject arbitrary operating system commands. This vulnerability is classified under CWE-78, which pertains to OS command injection flaws where untrusted input is incorporated into OS commands without adequate sanitization. The CVSS v3.1 base score of 9.6 reflects the high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is changed (S:C), indicating that exploitation can affect resources beyond the vulnerable component. The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning an attacker could execute arbitrary commands leading to full system compromise, data theft, or service disruption. No known exploits are currently reported in the wild, and no patches have been published yet. However, the vulnerability's nature and severity suggest it could be exploited by attackers controlling or impersonating MCP servers or intercepting communications to inject malicious payloads into the authorization_endpoint response URL. This could lead to remote code execution on client systems running the vulnerable mcp-remote version.

For European organizations, this vulnerability poses a significant risk, especially for those using mcp-remote version 0.0.5 in their infrastructure or development environments. Successful exploitation could lead to unauthorized remote code execution, allowing attackers to compromise sensitive data, disrupt operations, or pivot within networks. Given the high impact on confidentiality, integrity, and availability, organizations could face data breaches, operational downtime, and reputational damage. The requirement for user interaction means phishing or social engineering could be used to trigger the exploit, increasing the risk in environments with less stringent user security awareness. Additionally, since the vulnerability involves connecting to untrusted MCP servers, supply chain attacks or compromised third-party servers could be vectors. European entities in sectors such as finance, healthcare, critical infrastructure, and government are particularly at risk due to the sensitive nature of their data and the regulatory environment (e.g., GDPR) that mandates strict data protection and breach notification requirements.

To mitigate this vulnerability, European organizations should: 1) Immediately identify and inventory all instances of mcp-remote version 0.0.5 in their environment. 2) Restrict connections to only trusted MCP servers by implementing strict allowlists and verifying server authenticity through strong TLS configurations and certificate pinning where possible. 3) Employ network-level controls such as firewalls and intrusion detection/prevention systems to monitor and block suspicious traffic related to MCP communications. 4) Educate users about the risks of interacting with untrusted servers and the importance of verifying URLs and endpoints before authorizing connections. 5) Implement application-layer input validation and sanitization for any components interacting with MCP servers, if possible, to reduce injection risks. 6) Monitor for unusual command execution patterns or system behavior indicative of exploitation attempts. 7) Engage with the software vendor or community to obtain patches or updates addressing this vulnerability as soon as they become available and apply them promptly. 8) Consider deploying endpoint detection and response (EDR) solutions to detect and respond to potential exploitation attempts in real time.