CVE-2025-53540 in arduino-esp32
Summary
by MITRE • 07/07/2025
arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Several OTA update examples and the HTTPUpdateServer implementation are vulnerable to Cross-Site Request Forgery (CSRF). The update endpoints accept POST requests for firmware uploads without CSRF protection. This allows an attacker to upload and execute arbitrary firmware, resulting in remote code execution (RCE). This vulnerability is fixed in 3.2.1.
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Analysis
by VulDB Data Team • 07/07/2025
The vulnerability identified as CVE-2025-53540 affects the arduino-esp32 framework which serves as the core implementation for various ESP32 microcontroller families including ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6, and ESP32-H2 devices. This security flaw resides within the Over-The-Air (OTA) update functionality and HTTPUpdateServer implementation that are commonly used for firmware management in embedded IoT devices. The vulnerability manifests as a critical Cross-Site Request Forgery weakness that fundamentally compromises the security model of these embedded systems by allowing unauthorized firmware modifications through seemingly legitimate update processes. The affected components specifically handle POST requests for firmware uploads without implementing proper CSRF protection mechanisms, creating a significant attack surface for malicious actors who can leverage this weakness to execute arbitrary code on target devices.
The technical implementation of this vulnerability stems from the absence of anti-CSRF tokens or validation mechanisms within the firmware update endpoints. When an attacker crafts a malicious webpage or exploits an existing web interface that triggers a POST request to the vulnerable update server, the system processes the firmware upload without verifying the authenticity of the request origin. This design flaw aligns with CWE-352, which specifically addresses Cross-Site Request Forgery vulnerabilities in web applications and embedded systems. The vulnerability can be exploited through various attack vectors including phishing campaigns, malicious websites, or compromised networks where an attacker can manipulate the victim's browser to submit firmware update requests. The attack chain typically involves an attacker creating a malicious HTML page that automatically submits a POST request to the target device's update endpoint, bypassing any authentication mechanisms that might otherwise protect the system.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete system compromise and potential supply chain attacks. Once an attacker successfully uploads malicious firmware, they gain complete control over the target device, enabling them to modify system behavior, extract sensitive data, establish persistent backdoors, or use the compromised device as a pivot point for attacking other networked systems. This represents a critical Remote Code Execution (RCE) vulnerability that can affect millions of IoT devices running on ESP32 microcontrollers, particularly those deployed in industrial control systems, smart home environments, or security applications. The vulnerability affects not just individual devices but entire networks of interconnected IoT systems, as compromised devices can serve as entry points for broader network infiltration. The implications are particularly severe given that many ESP32-based devices operate in environments where physical security is limited and network access may be unauthenticated or poorly secured, making the exploitation of this CSRF vulnerability particularly dangerous.
Mitigation strategies for this vulnerability require immediate implementation of CSRF protection mechanisms within the firmware update endpoints, including the deployment of anti-CSRF tokens, request origin validation, and proper session management controls. The recommended solution involves upgrading to version 3.2.1 of the arduino-esp32 framework where the vulnerability has been addressed through proper CSRF token implementation and request validation. Organizations should also implement network segmentation, disable unnecessary OTA update functionality where possible, and deploy monitoring solutions to detect unauthorized firmware update activities. Additional defensive measures include implementing secure communication protocols such as HTTPS with proper certificate validation, restricting update endpoint access to trusted networks, and conducting regular security assessments of embedded systems. This vulnerability demonstrates the critical importance of applying security patches promptly in IoT environments and highlights the need for robust security controls in embedded systems that are often overlooked in traditional cybersecurity frameworks. The ATT&CK framework categorizes this vulnerability under T1547.001 for Application Access Tokens and T1059.001 for Command and Scripting Interpreter, reflecting the attack paths that leverage this weakness for system compromise and execution of malicious code.