CVE-2018-3935 in Home Camera 27US
Summary
by MITRE
An exploitable code execution vulnerability exists in the UDP network functionality of Yi Home Camera 27US 1.8.7.0D. A specially crafted set of UDP packets can allocate unlimited memory, resulting in denial of service. An attacker can send a set of packets to trigger this vulnerability.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-3935 represents a critical denial of service condition within the Yi Home Camera 27US firmware version 1.8.7.0D, specifically affecting the device's UDP network handling capabilities. This issue stems from improper memory management within the camera's network stack implementation, creating a scenario where maliciously crafted UDP packets can trigger uncontrolled memory allocation behavior. The vulnerability manifests when the device processes specially constructed UDP packets that exploit a flaw in how the system handles incoming network traffic, particularly in the context of UDP protocol processing. The affected device operates under the assumption that incoming UDP packets will conform to expected network protocols, but fails to implement adequate bounds checking or memory allocation limits for packet processing.
The technical flaw in this vulnerability resides in the lack of proper input validation and memory allocation controls within the camera's UDP packet handling routine. When the device receives UDP packets that exceed normal processing parameters, the system attempts to allocate memory without sufficient bounds checking, potentially leading to unlimited memory consumption. This memory allocation issue is classified as a memory leak or memory exhaustion vulnerability, where the system's memory management routines fail to properly limit the amount of memory that can be allocated during packet processing. The vulnerability operates at the network protocol level and can be triggered remotely without requiring authentication or physical access to the device. The underlying cause aligns with CWE-129, which addresses improper validation of the length of input data, and CWE-772, which deals with missing release of memory after effective lifetime, both of which are common patterns in embedded systems security flaws.
From an operational impact perspective, this vulnerability enables an attacker to remotely cause a denial of service condition that renders the Yi Home Camera 27US non-functional. The unlimited memory allocation can quickly consume all available system memory, causing the device to become unresponsive or crash entirely. This makes the camera unable to perform its primary function of video surveillance and network communication, effectively disabling the security monitoring capability that users rely upon. The impact extends beyond simple service disruption as it compromises the security infrastructure that organizations and individuals depend on for protection. The vulnerability can be exploited from any network location capable of reaching the device's network interface, making it particularly dangerous in environments where cameras are deployed without proper network segmentation or monitoring. This type of vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how embedded device vulnerabilities can create significant security risks in IoT deployments.
The recommended mitigation strategies for CVE-2018-3935 involve immediate firmware updates from the vendor to address the memory management flaw in the UDP packet handling code. Network administrators should implement proper network segmentation to limit access to affected devices and consider deploying network monitoring solutions that can detect anomalous UDP traffic patterns. Additionally, implementing rate limiting on UDP traffic to the affected device can help prevent exploitation, while regular security audits of IoT devices should be conducted to identify similar vulnerabilities in other networked equipment. The vulnerability demonstrates the importance of proper input validation and memory management in embedded systems, particularly in IoT devices where security updates may be infrequent or unavailable. Organizations should also consider implementing network-based intrusion detection systems that can identify and block suspicious UDP packet patterns that may indicate exploitation attempts.