CVE-2025-60687: Critical Command Injection Flaw Exposes ToToLink LR1200GB Routers

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Overview

CVE-2025-60687 is a medium-severity unauthenticated command injection vulnerability affecting the ToToLink LR1200GB Router running firmware version V9.1.0u.6619_B20230130. This flaw allows attackers to execute arbitrary commands on the router without needing any credentials. This vulnerability stems from improper input validation in the cstecgi.cgi binary, specifically within the sub_41EC68 function. Exploitation can lead to complete compromise of the device.

Technical Details

The vulnerability lies in the way the router handles the “imei” parameter within web requests. The cstecgi.cgi binary receives this parameter and performs a rudimentary check, verifying only that the input is 15 characters in length. Critically, it fails to sanitize the input for shell metacharacters. The “imei” parameter is then directly inserted into a system command using the sprintf() function, which in turn is executed via the system() function.

This direct injection of unsanitized user-controlled input allows an attacker to inject arbitrary commands into the executed system command. For example, an attacker could provide an “imei” value like this:

123456789012345; telnetd -p 1337 -l /bin/sh

This would inject the telnetd command, opening a telnet server on port 1337 that allows anyone to connect and execute commands as root, effectively giving the attacker complete control over the router.

CVSS Analysis

  • CVE ID: CVE-2025-60687
  • Severity: MEDIUM
  • CVSS Score: 6.5
  • Vector String (assumed): AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

The CVSS score of 6.5 reflects the vulnerability’s medium severity. The vulnerability is remotely exploitable (AV:N) with low attack complexity (AC:L) and requires no privileges (PR:N) or user interaction (UI:N). While the scope is unchanged (S:U), it can lead to partial confidentiality (C:L), integrity (I:L), and availability (A:L) impact, as an attacker can gain partial control over the router, potentially accessing sensitive information, modifying settings, and disrupting network services.

Possible Impact

Successful exploitation of CVE-2025-60687 can have severe consequences:

  • Complete Router Compromise: Attackers can gain complete control over the router, allowing them to modify settings, install malware, and intercept network traffic.
  • Data Theft: Sensitive data transmitted through the router, such as login credentials and personal information, could be intercepted and stolen.
  • Botnet Recruitment: Compromised routers can be recruited into botnets, used to launch distributed denial-of-service (DDoS) attacks, or mine cryptocurrency.
  • Network Disruption: Attackers can disrupt network services by modifying router configurations or causing the device to crash.

Mitigation and Patch Steps

The primary mitigation strategy is to update the router’s firmware to a patched version that addresses the vulnerability. Check the ToToLink website for available updates.

If an update is not immediately available, consider these temporary workarounds:

  • Disable Remote Access: If possible, disable remote administration access to the router to reduce the attack surface.
  • Monitor Network Traffic: Monitor network traffic for suspicious activity, such as unauthorized access attempts or unusual data transfers.
  • Use a Firewall: Ensure your network firewall is properly configured to block unauthorized access to the router.
  • Consider alternative Routers: If security updates are not provided promptly, strongly consider replacing the router with a model from a vendor known for its strong security practices and prompt security updates.

Unfortunately, since exploitation requires sending the malicious data as the IMEI parameter, simply changing the device’s IMEI from within the router’s web interface will *not* mitigate this vulnerability.

References

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