CVE-2022-40717 in DIR-2150
Summary
by MITRE • 01/26/2023
This vulnerability allows network-adjacent attackers to execute arbitrary code on affected D-Link DIR-2150 4.0.1 routers. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the anweb service, which listens on TCP ports 80 and 443 by default. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-15727.
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Analysis
by VulDB Data Team • 01/26/2023
This vulnerability represents a critical buffer overflow flaw in D-Link DIR-2150 routers running firmware version 4.0.1, where the anweb service operates as a privileged component listening on standard HTTP and HTTPS ports 80 and 443. The vulnerability classifies under CWE-121 Stack-based Buffer Overflow, specifically manifesting in improper input validation during data processing within the web server component. Attackers exploiting this weakness can craft malicious payloads that exceed the predetermined buffer boundaries, causing memory corruption that enables arbitrary code execution with root privileges.
The technical implementation of this vulnerability stems from insufficient bounds checking within the anweb service's handling of user-supplied data streams. When network-adjacent attackers send specially crafted requests containing oversized input parameters to the router's web interface, the system fails to validate the length constraints before copying data into fixed-size stack buffers. This fundamental flaw in input sanitization creates a direct pathway for memory corruption that can be exploited through return-oriented programming or direct code injection techniques. The vulnerability's accessibility without authentication requirements significantly amplifies its threat potential, as it eliminates the need for credential compromise.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and persistent access. Successful exploitation allows attackers to gain root-level privileges on the affected router, enabling them to modify network configurations, install malicious firmware, establish backdoors, or use the device as a pivot point for broader network infiltration. This aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1021.001 for remote services, as attackers can leverage the compromised router for lateral movement and persistent access within network environments. The vulnerability affects not only individual device security but also poses risks to entire network infrastructures that rely on these devices for routing and connectivity.
Mitigation strategies should prioritize immediate firmware updates from D-Link to address the underlying buffer overflow condition, though organizations may need to implement network-level restrictions such as firewall rules blocking external access to TCP ports 80 and 443 on affected devices. Network segmentation and monitoring of suspicious traffic patterns can help detect exploitation attempts, while disabling unnecessary web services and implementing strong access controls for administrative interfaces provides additional defense layers. The vulnerability demonstrates the critical importance of input validation in network services and aligns with security best practices outlined in NIST SP 800-144 and ISO/IEC 27001 standards for protecting against buffer overflow attacks through proper software design and code review processes.