CVE-2021-28839 : Exploit Details and Defense Strategies
Learn about CVE-2021-28839, a Null Pointer Dereference vulnerability in D-Link DAP series routers. Understand the impact, affected systems, and mitigation steps for enhanced security.
A Null Pointer Dereference vulnerability has been identified in D-Link DAP series routers, potentially leading to a security issue. Learn more about this CVE below.
Understanding CVE-2021-28839
This section provides insights into what CVE-2021-28839 entails.
What is CVE-2021-28839?
The CVE-2021-28839 vulnerability is present in the upload_certificate function of the sbin/httpd binary in various D-Link DAP series routers. It allows an attacker to trigger a NULL pointer dereference by sending a specific HTTP GET request.
The Impact of CVE-2021-28839
Exploitation of this vulnerability could result in a denial of service (DoS) attack, leading to system crashes or other disruptions.
Technical Details of CVE-2021-28839
In this section, we delve deeper into the technical aspects of CVE-2021-28839.
Vulnerability Description
The vulnerability arises from the strrchr function in the upload_certificate function processing NULL as its first argument, causing a NULL pointer dereference.
Affected Systems and Versions
The vulnerability affects D-Link DAP-2310, DAP-2330, DAP-2360, DAP-2553, DAP-2660, DAP-2690, DAP-2695, DAP-3320, and DAP-3662 routers with specific firmware versions.
Exploitation Mechanism
By sending a crafted HTTP GET request to the affected routers, an attacker could exploit the NULL pointer dereference vulnerability.
Mitigation and Prevention
Discover how to mitigate and prevent vulnerabilities similar to CVE-2021-28839 in the following section.
Immediate Steps to Take
Users are advised to update the router firmware to the latest version provided by D-Link. Additionally, implement network security measures to mitigate potential attacks.
Long-Term Security Practices
Regularly monitor security bulletins from D-Link and other sources to stay informed about potential vulnerabilities and best practices to enhance network security.
Patching and Updates
Apply security patches and firmware updates released by D-Link promptly to address known vulnerabilities and improve the overall security posture of the network.