Overview
CVE-2025-60689 is a critical security vulnerability affecting Linksys E1200 v2 routers running firmware version E1200_v2.0.11.001_us.tar.gz. This vulnerability allows unauthenticated remote attackers to execute arbitrary commands on the affected device. The root cause lies in insufficient input sanitization within the Start_EPI function of the httpd binary.
Technical Details
The vulnerability stems from the way the Start_EPI function handles user-supplied CGI parameters. Specifically, the following parameters are vulnerable: wl_ant, wl_ssid, wl_rate, ttcp_num, ttcp_ip, and ttcp_size. These parameters are directly concatenated into system command strings without proper validation or sanitization. The resulting command string is then executed via the wl_exec_cmd function. Because no authentication is required to access and manipulate these CGI parameters, any attacker capable of sending HTTP requests to the router can exploit this flaw.
An attacker could craft a malicious HTTP request containing specially crafted values for the vulnerable parameters. These values could include shell metacharacters, allowing the attacker to inject arbitrary commands that will be executed with elevated privileges on the router’s operating system. For example, injecting a command like ;reboot; would cause the router to reboot.
The vulnerable code is located within the httpd binary. Reverse engineering and dynamic analysis confirm the lack of proper input validation before executing the system commands.
CVSS Analysis
The vulnerability has been assigned a CVSS score of 5.4 (Medium). This score reflects the following characteristics:
- Attack Vector (AV): Network (N) – The vulnerability can be exploited over a network.
- Attack Complexity (AC): Low (L) – The attack requires little specialized knowledge or resources.
- Privileges Required (PR): None (N) – No privileges are required to exploit the vulnerability.
- User Interaction (UI): None (N) – No user interaction is required to exploit the vulnerability.
- Scope (S): Unchanged (U) – An exploited vulnerability can only affect resources managed by the same security authority.
- Confidentiality Impact (C): Low (L) – Limited information disclosure.
- Integrity Impact (I): Low (L) – Limited modification of data.
- Availability Impact (A): Low (L) – Limited disruption of services.
Possible Impact
Successful exploitation of CVE-2025-60689 can have significant consequences:
- Remote Code Execution: Attackers can execute arbitrary commands on the router, potentially gaining complete control of the device.
- Data Theft: Attackers could access sensitive information stored on the router, such as Wi-Fi passwords or network configurations.
- Malware Installation: Attackers can install malware on the router, turning it into a botnet node or using it to launch attacks against other devices on the network.
- Denial of Service (DoS): Attackers can cause the router to crash or become unresponsive, disrupting network connectivity for all connected devices.
- Router Configuration Changes: Attackers can modify router settings, potentially redirecting traffic to malicious servers or creating backdoors for future access.
Mitigation and Patch Steps
The primary mitigation strategy is to update the router’s firmware to a patched version that addresses this vulnerability. Check the Linksys support website for available firmware updates. Unfortunately, given the age of the E1200 v2, it’s possible no patch will be released.
If a firmware update is not available, consider the following workarounds, although they may not be fully effective:
- Disable Remote Management: If possible, disable remote management access to the router. This prevents external attackers from accessing the router’s web interface.
- Use a Strong Password: While not directly addressing the command injection, using a strong and unique password for the router’s web interface can help prevent unauthorized access to other settings.
- Consider Replacing the Router: If a patch is unavailable and the workarounds are insufficient, the most secure option is to replace the router with a more modern and secure device.