CVE-2019-3948 in IP2M-841B
Summary
by MITRE
The Amcrest IP2M-841B IP camera firmware version V2.520.AC00.18.R does not require authentication to access the HTTP endpoint /videotalk. An unauthenticated, remote person can connect to this endpoint and listen to the audio the camera is capturing.
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Analysis
by VulDB Data Team • 08/10/2024
The Amcrest IP2M-841B IP camera represents a significant security vulnerability through its improper authentication handling within the firmware version V2.520.AC00.18.R. This specific flaw manifests as a critical weakness in the device's access control mechanisms, where the HTTP endpoint /videotalk operates without requiring any form of authentication verification. The vulnerability stems from the camera's design failing to implement proper authorization checks before granting access to its audio capture functionality, creating an unintended backdoor for malicious actors.
The technical implementation of this vulnerability involves the camera's web server configuration where the /videotalk endpoint remains publicly accessible without any authentication requirements. This endpoint serves audio data captured by the camera's microphone, and the lack of authentication means that any remote attacker can establish a connection to the device and begin streaming the audio feed. The flaw operates at the application layer of the network stack, where the HTTP protocol is used to deliver audio content without proper session management or user verification processes. This represents a direct violation of fundamental security principles that should be implemented for any network-accessible device handling sensitive audio data.
The operational impact of this vulnerability extends far beyond simple privacy concerns, creating potential risks for both personal and commercial security environments. Remote attackers can exploit this flaw to conduct unauthorized surveillance activities, potentially capturing sensitive conversations or audio information from locations where the camera is deployed. The vulnerability affects any environment where the camera is used for security monitoring, including residential properties, commercial buildings, and industrial facilities, where the unauthorized access to audio feeds could compromise ongoing security operations. This weakness fundamentally undermines the trust model that security devices are expected to maintain, as it allows complete access to audio data without any verification of the user's authorization status.
The vulnerability aligns with CWE-284, which addresses improper access control mechanisms, and represents a clear violation of the principle of least privilege that should govern all network-accessible services. From an attack perspective, this flaw maps directly to ATT&CK technique T1046, where adversaries probe for open ports and services, and T1566, involving social engineering through unauthorized access to audio feeds. The attack surface is particularly concerning because it requires no specialized tools or advanced techniques beyond basic network connectivity and HTTP protocol understanding. Security professionals should consider this vulnerability as a critical risk factor in any network environment where Amcrest IP2M-841B devices are deployed, as it provides immediate access to audio data without any form of user authentication.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from Amcrest to address the authentication flaw, while network segmentation and access control measures can provide additional layers of protection. Organizations should implement network monitoring to detect unauthorized access attempts to the affected endpoint, and consider disabling the /videotalk service entirely if it is not required for operational purposes. The recommended approach involves both immediate remediation through vendor-provided patches and longer-term architectural changes to ensure proper authentication enforcement for all network-accessible services. Security teams should also conduct comprehensive audits of all network devices to identify similar authentication weaknesses that may exist in other security equipment within their infrastructure.