CVE-2025-54135
8.5Cursor · Cursor
A vulnerability in the Cursor code editor allows attackers to write files without user approval, enabling remote code execution via indirect prompt injection and malicious configuration file creation.
Executive summary
A critical vulnerability in Cursor versions prior to 1.3.9 permits unauthorized file manipulation and potential remote code execution, posing a significant risk to development environments.
Vulnerability
This issue involves improper neutralization of special elements and inclusion of functionality from untrusted control spheres, allowing a low-privileged attacker to write to sensitive workspace files and execute arbitrary commands. The exploit chain leverages indirect prompt injection to hijack the editor context and create or modify system files without explicit user consent.
Business impact
The ability for an unauthenticated or low-privileged attacker to achieve remote code execution on a developer workstation presents a severe risk to intellectual property and organizational integrity. Given the CVSS score of 8.5, this flaw could lead to full system compromise, the exfiltration of sensitive source code, or the injection of malicious backdoors into software projects.
Remediation
Immediate Action: Update the Cursor application to version 1.3.9 or later immediately to incorporate the necessary security patches.
Proactive Monitoring: Review workspace configuration files, particularly those located in the .cursor directory, for unauthorized modifications or unexpected additions.
Compensating Controls: Restrict the execution of AI-based coding tools within high-security or production-critical environments until updates are verified, and maintain robust endpoint detection and response (EDR) solutions to identify suspicious child processes spawned by the editor.
Exploitation status
Public Exploit Available: Yes, a public proof-of-concept exists as documented in GitHub repositories.
Analyst recommendation
This vulnerability represents a high-severity threat to any organization utilizing Cursor for software development. The combination of remote code execution potential and the existence of public proof-of-concept material necessitates an immediate upgrade to version 1.3.9. Security teams should prioritize this patch across all developer workstations to prevent potential supply chain or internal system compromise.