CVE-2023-43862

A newly discovered vulnerability in D-Link DIR-619L B1 2.02 wireless router firmware allows potential attackers to exploit a buffer overflow condition within the web-based management interface. This buffer overflow occurs in the formLanguageChange function, which is responsible for handling language changes in the web interface. The successful exploitation of this vulnerability may give the attacker complete control over the affected device and access to sensitive information.

The vulnerability has been assigned the Common Vulnerabilities and Exposures identifier CVE-2023-43862. This ID provides a unique reference to easily track and gather more information about the vulnerability. For more details regarding this vulnerability, please refer to the CVE record here.

Technical Details

The vulnerable function, formLanguageChange, utilizes a strncpy call that copies a user-supplied value into a fixed-size buffer. An attacker can provide an oversized value, leading to buffer overflow and overwriting memory outside the allocated buffer.

The following code snippet shows the vulnerable strncpy call

char buffer[256];
strncpy(buffer, user_supplied_value, sizeof(buffer));

Exploitation

To exploit this vulnerability, an attacker can send a crafted HTTP POST request to the web-based management interface with an oversized value for the language parameter. This will cause a buffer overflow, as demonstrated in the following HTTP POST request:

POST /formLanguageChange HTTP/1.1
Content-Length: 500
Content-Type: application/x-www-form-urlencoded

language=AAAAAAAA...[500 'A' characters]...AAAAAAAA

This exploit may result in the execution of arbitrary code or a denial of service condition, depending on how the overflowed memory is used.

To mitigate this vulnerability

1. Update the D-Link DIR-619L B1 firmware to version 2.03 or later, which contains patches to address this vulnerability.

2. Limit access to the web-based management interface. Restrict external access to the management interface by implementing proper access controls, such as IP whitelisting and strong authentication.

Conclusion

This vulnerability highlights the importance of securing your network devices and maintaining their security. Regularly updating your firmware and following best practices can minimize the risk of exploitation of such vulnerabilities.

Original References

- CVE-2023-43862 - National Vulnerability Database (NVD) Record

- D-Link DIR-619L B1 Security Advisory

Timeline

Published on: 09/28/2023 14:15:22 UTC
Last modified on: 09/29/2023 04:32:29 UTC