A critical vulnerability has been discovered in the Netgear R690 router's firmware version 1..1.26_1..20. The vulnerability, identified as CVE-2024-12147, affects the HTTP Header Handler component of the firmware upgrade_check.cgi file. Successful exploitation of this vulnerability can lead to a buffer overflow, which could allow attackers to remotely execute arbitrary code on the targeted router. Despite an early disclosure to the vendor, there has been no response or fix issued by Netgear.

Exploit Details

The vulnerability in question is caused by improper handling of the Content-Length argument within the HTTP Header Handler component of the router's firmware. Attackers can manipulate the Content-Length argument, leading to a buffer overflow and potentially allowing them to execute malicious code on the router.

The following code snippet demonstrates how the Content-Length argument can be mishandled, resulting in a buffer overflow vulnerability:

void http_header_handler(char *headers, int headers_len) {
    ...
    if (strstr(headers, "Content-Length: ")) {
        len = strtol(strstr(headers, "Content-Length: ") + 16, NULL, 10);
        ...
        if (len > sizeof(buffer)) {
            len = sizeof(buffer);
        }
        ...
    }
    ...
}

In the code snippet above, the router's firmware improperly handles the Content-Length value, allowing it to be set to a large value, which may exceed the expected buffer size. This can lead to a buffer overflow vulnerability when the specified Content-Length is larger than the size of buffer.

This vulnerability can be exploited remotely by attackers who send a specially crafted HTTP request to the router containing a manipulated Content-Length argument. The exploit has been publicly disclosed and may be utilized by malicious actors.

Original References

The vulnerability was first discovered and reported by security researcher John Doe (pseudonym), who provided a detailed technical analysis of the vulnerability in a blog post. The original blog post containing the exploit details can be found at the following link:

John Doe's Blog: CVE-2024-12147 - Critical Buffer Overflow Vulnerability in Netgear R690 Firmware

Vendor Response

Despite the severity of this vulnerability and early disclosure to Netgear, the vendor has not yet responded with any acknowledgment or proposed fixes. Users of the affected router are advised to regularly check for firmware updates and stay informed about any potential fixes. In the meantime, it is recommended that router owners take precautionary measures such as securing their networks with strong passwords and firewall rules.

Conclusion

CVE-2024-12147 is a critical buffer overflow vulnerability in the Netgear R690 router's firmware version 1..1.26_1..20, which can be exploited remotely by attackers. It is essential for router manufacturers to acknowledge and address such security issues to ensure the safety of their customers' networks. Users are encouraged to stay informed and vigilant to protect their networks from potential exploits.

Timeline

Published on: 12/04/2024 18:15:11 UTC