CVE-2017-8414 in DCS-1100
Summary
by MITRE
An issue was discovered on D-Link DCS-1100 and DCS-1130 devices. The binary orthrus in /sbin folder of the device handles all the UPnP connections received by the device. It seems that the binary performs a sprintf operation at address 0x0000A3E4 with the value in the command line parameter "-f" and stores it on the stack. Since there is no length check, this results in corrupting the registers for the function sub_A098 which results in memory corruption.
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Analysis
by VulDB Data Team • 10/15/2023
The vulnerability identified in CVE-2017-8414 affects D-Link DCS-1100 and DCS-1130 IP camera devices, representing a critical memory corruption flaw within the device's UPnP implementation. This vulnerability resides in the orthrus binary located in the /sbin directory, which serves as the primary handler for all Universal Plug and Play connections received by these network cameras. The orthrus binary operates as a critical component in the device's network functionality, managing external communication protocols that enable device discovery and automatic port mapping. The flaw manifests specifically within the command line argument processing mechanism, where the binary fails to validate input length before performing string operations.
The technical exploitation occurs at memory address 0x0000A3E4 where the sprintf function is invoked with the value provided through the command line parameter "-f". This particular implementation lacks any bounds checking or input validation mechanisms that would normally prevent buffer overflow conditions. The absence of length constraints allows an attacker to provide an overly long string parameter that exceeds the allocated stack buffer space. When sprintf processes this unvalidated input, it writes beyond the intended buffer boundaries, leading to corruption of adjacent stack memory locations including register contents and return addresses. This memory corruption directly impacts the function sub_A098 which executes at address 0x0000A098, causing unpredictable behavior and potential code execution opportunities.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a potential pathway for remote code execution within the device's operating environment. Attackers can leverage this flaw to manipulate the execution flow of the orthrus binary, potentially gaining unauthorized access to the device's command execution capabilities. The vulnerability affects devices running firmware versions where the orthrus binary fails to implement proper input sanitization, making the entire D-Link camera product line susceptible to exploitation. The nature of this flaw aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of unsafe string handling in embedded systems. This vulnerability demonstrates the critical importance of input validation in network-facing services, particularly in IoT devices where such flaws can provide complete system compromise.
The exploitation of this vulnerability requires minimal prerequisites, as it can be triggered through UPnP protocol interactions that are typically enabled by default on these devices. Network-based attackers can potentially send malformed UPnP packets containing maliciously crafted "-f" parameters to exploit the buffer overflow condition. The attack surface is particularly concerning given that these cameras are often deployed in unsecured environments and may be accessible from the internet without proper network segmentation. Mitigation strategies should focus on firmware updates from D-Link that implement proper input validation and bounds checking within the orthrus binary. Additionally, network administrators should consider disabling UPnP functionality on these devices when not actively required, and implement proper network segmentation to limit exposure. This vulnerability also highlights the broader ATT&CK framework concept of privilege escalation through exploitation of insecure input handling, where attackers can leverage such flaws to move laterally within network environments. Organizations should prioritize patch management for embedded devices and implement network monitoring to detect suspicious UPnP traffic patterns that may indicate exploitation attempts.