CVE-2021-43722 : Vulnerability Insights and Analysis

D-Link DIR-645 1.03 A1 is vulnerable to Buffer Overflow due to an issue in the hnap_main function in the cgibin handler.

Understanding CVE-2021-43722

The vulnerability in D-Link DIR-645 1.03 A1 allows for a Buffer Overflow attack.

What is CVE-2021-43722?

The hnap_main function in the cgibin handler of D-Link DIR-645 1.03 A1 uses sprintf without limiting the size, leading to a Buffer Overflow vulnerability.

The Impact of CVE-2021-43722

Attackers can exploit this vulnerability to execute malicious code or crash the system by overflowing the stack with crafted soapaction header values.

Technical Details of CVE-2021-43722

The technical aspects of the vulnerability in D-Link DIR-645 1.03 A1.

Vulnerability Description

The hnap_main function in the cgibin handler uses sprintf to format the soapaction header onto the stack without adequate size validation, enabling a Buffer Overflow.

Affected Systems and Versions

Product: D-Link DIR-645 1.03 A1
Vendor: D-Link
Version: 1.03 A1
Status: Affected

Exploitation Mechanism

Attackers send specially crafted soapaction header values to trigger the Buffer Overflow in the cgibin handler, potentially leading to arbitrary code execution.

Mitigation and Prevention

Steps to mitigate and prevent exploitation of CVE-2021-43722.

Immediate Steps to Take

Update the firmware of the D-Link DIR-645 to a non-vulnerable version if available.
Restrict network access to vulnerable devices.
Monitor network traffic for any signs of exploit attempts.

Long-Term Security Practices

Regularly update firmware and software to patch known vulnerabilities.
Implement network segmentation to limit the impact of successful attacks.
Conduct security assessments and penetration testing to identify and remediate weaknesses.

Patching and Updates

Check the official D-Link security bulletin and apply recommended patches.
Follow best practices for secure coding to prevent similar vulnerabilities in the future.