Overview
A critical security vulnerability, identified as CVE-2025-60693, has been discovered in Linksys E1200 v2 routers running firmware version E1200_v2.0.11.001_us.tar.gz. This vulnerability is a stack-based buffer overflow that exists within the get_merge_mac function of the httpd binary. Successful exploitation allows unauthenticated remote attackers to execute arbitrary code or cause a denial of service (DoS).
Technical Details
The vulnerability stems from insufficient bounds checking in the get_merge_mac function. This function concatenates user-supplied CGI parameters of the form <parameter>_0 through <parameter>_5 into a fixed-size buffer. During the concatenation process, colon delimiters are appended between the parameter values. Due to the lack of input validation, an attacker can craft a malicious HTTP request with overly long parameter values, causing the buffer to overflow. This overflow overwrites data on the stack, potentially leading to arbitrary code execution.
Specifically, the attacker can control the content written to the stack, enabling them to hijack program execution flow. The lack of authentication requirements makes this vulnerability particularly dangerous.
CVSS Analysis
- CVE ID: CVE-2025-60693
- Severity: MEDIUM
- CVSS Score: 6.5
- CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (Example – adjust based on actual calculation)
A CVSS score of 6.5 indicates a MEDIUM severity vulnerability. While not critical, it still poses a significant risk due to its remote exploitability and potential for denial of service.
Possible Impact
The exploitation of CVE-2025-60693 can lead to several detrimental consequences:
- Remote Code Execution: Attackers can execute arbitrary code on the affected router, potentially gaining complete control of the device.
- Denial of Service (DoS): Attackers can crash the router, rendering it unusable and disrupting network connectivity.
- Network Compromise: A compromised router can be used as a pivot point to attack other devices on the network, potentially exposing sensitive data or causing further damage.
Mitigation and Patch Steps
The following steps are recommended to mitigate the risk posed by CVE-2025-60693:
- Apply Firmware Update: Check the Linksys official website for a firmware update that addresses this vulnerability. Applying the latest firmware is the most effective way to resolve the issue.
- Disable Remote Management: If a firmware update is not immediately available, consider disabling remote management access to the router. This reduces the attack surface by preventing external access to the router’s web interface.
- Monitor Network Traffic: Monitor network traffic for suspicious activity, such as unusual HTTP requests targeting the router.
We strongly advise users of Linksys E1200 v2 routers to take immediate action to protect their devices.
