CVE-2018-17067 in DIR-816 A2
Summary
by MITRE
An issue was discovered on D-Link DIR-816 A2 1.10 B05 devices. A very long password to /goform/formLogin could lead to a stack-based buffer overflow and overwrite the return address.
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Analysis
by VulDB Data Team • 03/24/2020
The vulnerability identified as CVE-2018-17067 affects D-Link DIR-816 A2 1.10 B05 wireless routers, representing a critical stack-based buffer overflow condition that can be exploited to compromise the device's operational integrity. This issue manifests through the web-based administration interface when processing login requests via the /goform/formLogin endpoint, where the device fails to properly validate input length before copying user-supplied data into a fixed-size buffer on the stack. The flaw stems from inadequate bounds checking mechanisms that allow attackers to supply excessively long password strings, causing the program to overwrite adjacent memory locations including the return address stored on the call stack.
The technical exploitation of this vulnerability follows a classic buffer overflow attack pattern where an attacker crafts a malicious input that exceeds the allocated buffer size, typically measured in bytes, and then manipulates the overwritten return address to redirect program execution to malicious code or previously established code within the application. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, which is classified as a fundamental memory safety issue that has been consistently documented in the CWE database as one of the most prevalent and dangerous classes of software flaws. The attack vector leverages the device's web interface, making it accessible over the network and potentially exploitable from remote locations without requiring physical access to the device.
The operational impact of this vulnerability extends beyond simple denial of service or unauthorized access, as successful exploitation could enable attackers to execute arbitrary code on the affected router, potentially leading to complete device compromise, persistent backdoor access, or the ability to redirect network traffic through the compromised device. The router's administrative interface becomes a potential entry point for attackers seeking to establish persistent access to the local network, as the compromised device could be used to monitor network traffic, redirect connections to malicious sites, or serve as a pivot point for attacking other devices within the network. This vulnerability represents a significant risk to network security as it allows attackers to gain administrative control over network infrastructure components without requiring legitimate credentials.
Mitigation strategies for CVE-2018-17067 should include immediate firmware updates from D-Link to address the buffer overflow condition, as well as network segmentation to limit access to administrative interfaces and implement proper input validation at the application level. Network administrators should also consider implementing intrusion detection systems to monitor for unusual traffic patterns that might indicate exploitation attempts, and establish secure remote access practices that minimize exposure of administrative interfaces to untrusted networks. The vulnerability highlights the importance of proper input validation and memory management practices in embedded systems, as outlined in various cybersecurity frameworks including the NIST Cybersecurity Framework and the MITRE ATT&CK matrix, where such vulnerabilities are categorized under the technique of "Exploitation for Privilege Escalation" and "Command and Control" activities. Organizations should also implement regular security assessments of network infrastructure devices to identify similar vulnerabilities that might exist in other embedded systems or network equipment.