Overview
The CVE-2025-55847 vulnerability represents a significant potential risk to the integrity, confidentiality, and availability of systems running the Wavlink M86X3A_V240730. This vulnerability is a buffer overflow issue, specifically located in the /cgi-bin/ExportAllSettings.cgi file. Buffer overflows are notorious for their potential to allow attackers to execute arbitrary code and potentially take full control of a system. This post will dive into the details of the vulnerability to help you understand what it is, how it works, and what steps you can take to mitigate the risk it poses.
The importance of understanding and addressing this vulnerability can’t be overstated. With a CVSS Severity Score of 8.8, it’s classified as a high-severity issue. The potential impacts, including system compromise or data leakage, could have serious consequences for any business or individual affected.
Vulnerability Summary
CVE ID: CVE-2025-55847
Severity: High (8.8 CVSS Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise, potential data leakage
Affected Products
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Product | Affected Versions
Wavlink M86X3A_V240730 | All versions prior to the patch
How the Exploit Works
The vulnerability lies in the lack of proper input validation in the Cookie parameter of the /cgi-bin/ExportAllSettings.cgi file. If an attacker sends an excessively long input data to this parameter, it can cause a buffer overflow. Buffer overflows are dangerous because they can allow an attacker to overwrite memory, potentially leading to arbitrary code execution or a denial of service (DoS) attack on the system.
Conceptual Example Code
Below is a conceptual example of how the vulnerability might be exploited. This could be a sample HTTP request that triggers the buffer overflow:
GET /cgi-bin/ExportAllSettings.cgi HTTP/1.1
Host: vulnerable-host.com
Cookie: OVERFLOW_DATAIn this example, OVERFLOW_DATA would be a long string of characters designed to cause the buffer overflow. The exact nature of the string would depend on the specifics of the system’s memory layout and the code surrounding the vulnerable parameter.
Mitigation Guidance
It’s recommended to apply the vendor patch as soon as it becomes available. If the patch is not yet available or can’t be applied immediately, using a web application firewall (WAF) or an intrusion detection system (IDS) could help as a temporary mitigation measure. These systems could potentially detect and block attempts to exploit the vulnerability. However, they should not be seen as a permanent solution, and applying the official patch should remain the top priority.
