CVE-2021-3555 in 2K Indoor Camera
Summary
by MITRE • 05/31/2022
A Buffer Overflow vulnerability in the RSTP server component of Eufy Indoor 2K Indoor Camera allows a local attacker to achieve remote code execution. This issue affects: Eufy Indoor 2K Indoor Camera 2.0.9.3 version and prior versions.
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Analysis
by VulDB Data Team • 06/04/2022
The CVE-2021-3555 vulnerability represents a critical buffer overflow flaw within the RSTP server component of Eufy Indoor 2K Indoor Camera devices, specifically impacting firmware versions 2.0.9.3 and earlier. This vulnerability stems from improper input validation mechanisms within the Real-Time Streaming Protocol server implementation, creating a condition where maliciously crafted network packets can exceed the allocated buffer space and overwrite adjacent memory regions. The flaw exists in the camera's network service handling routines that process incoming RSTP streams without adequate bounds checking, allowing attackers to exploit this weakness through carefully constructed data payloads.
The technical exploitation of this vulnerability occurs through local network access, where an attacker can send specially crafted RSTP packets to the affected camera device. When the camera's RSTP server processes these malformed packets, the buffer overflow condition triggers memory corruption that can be leveraged to overwrite return addresses and function pointers within the execution stack. This memory corruption allows an attacker to redirect program execution flow and potentially inject malicious code into the camera's operating system. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how insufficient input validation can create remote code execution pathways in embedded network devices.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables full compromise of the affected camera device. Once exploited, attackers can gain persistent access to the camera's system, potentially allowing them to capture continuous video feeds, access stored media files, modify device configurations, or use the compromised camera as a pivot point for further attacks within the local network. The vulnerability particularly affects IoT security posture since it demonstrates how consumer-grade surveillance equipment can contain critical flaws that make them attractive targets for cybercriminals. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for command and scripting interpreter and T1046 for network service scanning, as attackers would likely use this vulnerability to establish persistent access and expand their network reconnaissance efforts.
Mitigation strategies for CVE-2021-3555 should prioritize immediate firmware updates from the manufacturer, as the vendor has likely released patches addressing the buffer overflow condition in newer firmware versions. Network segmentation and access controls should be implemented to limit local network access to these devices, while monitoring systems should be deployed to detect anomalous RSTP traffic patterns that might indicate exploitation attempts. Device administrators should also consider disabling unused network services and implementing network intrusion detection systems to identify potential exploitation attempts. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly in IoT devices where the attack surface is often expanded by network connectivity features. Organizations should also conduct regular vulnerability assessments of their IoT infrastructure to identify similar buffer overflow conditions that might exist in other networked devices within their environment.