CVE-2019-5040 in Nest Cam IQ Indoor
Summary
by MITRE
An exploitable information disclosure vulnerability exists in the Weave MessageLayer parsing of Openweave-core version 4.0.2 and Nest Cam IQ Indoor version 4620002. A specially crafted weave packet can cause an integer overflow to occur, resulting in PacketBuffer data reuse. An attacker can send a packet to trigger this vulnerability.
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Analysis
by VulDB Data Team • 11/27/2023
The CVE-2019-5040 vulnerability represents a critical information disclosure flaw within the Weave MessageLayer implementation of Openweave-core version 4.0.2 and Nest Cam IQ Indoor version 4620002. This vulnerability stems from improper handling of packet data structures during message parsing operations, creating a pathway for malicious actors to exploit integer overflow conditions that ultimately lead to data corruption and potential information leakage. The flaw specifically manifests in the PacketBuffer management system where the integer overflow occurs during packet processing, causing the system to reuse memory buffers that should remain allocated or properly deallocated. This type of vulnerability falls under CWE-190, which categorizes integer overflow conditions that can result in memory corruption and arbitrary code execution. The attack vector requires a remote attacker to craft and send a specially formatted weave packet to the vulnerable device, making this particularly dangerous in IoT environments where devices may be exposed to untrusted network traffic. The vulnerability's impact extends beyond simple information disclosure as the buffer reuse can potentially lead to more severe consequences including system instability, denial of service conditions, or even privilege escalation depending on the specific implementation details and surrounding system architecture.
The technical exploitation of this vulnerability leverages the integer overflow condition within the Weave MessageLayer parsing logic to manipulate buffer allocation and deallocation sequences. When processing a maliciously crafted weave packet, the system's integer overflow causes the PacketBuffer management code to compute incorrect buffer sizes or offsets, leading to the reuse of previously allocated memory regions. This memory corruption can result in data leakage from adjacent memory locations, potentially exposing sensitive information such as authentication credentials, system configuration data, or cryptographic keys stored within the device's memory space. The vulnerability demonstrates characteristics consistent with ATT&CK technique T1059.007, which involves the use of command and scripting interpreters, as the memory corruption can be leveraged to extract information through various data exfiltration methods. The integer overflow condition specifically affects the buffer management subsystem where the system fails to properly validate input packet sizes before performing arithmetic operations that determine buffer allocation parameters, creating a predictable pattern of memory corruption that can be systematically exploited by adversaries with network access to the target device.
The operational impact of CVE-2019-5040 extends significantly within IoT and connected device environments where the affected devices operate in potentially unsecured network conditions. Devices running vulnerable versions of Openweave-core or Nest Cam IQ Indoor systems become susceptible to information disclosure attacks that can compromise user privacy and system integrity. The vulnerability's remote exploitation capability means that attackers do not require physical access to the devices, making it particularly concerning for security-conscious organizations deploying these products. The buffer reuse condition can lead to cascading failures within the device's network stack, potentially causing service disruption or complete system failure. Organizations using these vulnerable systems face risks of unauthorized access to surveillance footage, network credentials, and other sensitive data that could be extracted through the information disclosure mechanism. The vulnerability's presence in both Openweave-core and Nest Cam IQ Indoor versions indicates a broader ecosystem impact, suggesting that similar flaws may exist in other devices utilizing the same Weave protocol implementation. Security professionals must consider this vulnerability in the context of IoT device security frameworks and the increasing reliance on connected devices in enterprise and residential environments, where such information disclosure vulnerabilities can serve as initial access vectors for more sophisticated attacks.
Mitigation strategies for CVE-2019-5040 should prioritize immediate firmware updates from vendors to address the integer overflow condition within the Weave MessageLayer parsing logic. Organizations should implement network segmentation and access controls to limit exposure of vulnerable devices to untrusted network segments, reducing the attack surface for remote exploitation attempts. The implementation of network monitoring solutions capable of detecting and alerting on malformed weave packets can provide early warning of exploitation attempts targeting this vulnerability. Security teams should conduct comprehensive vulnerability assessments of their IoT deployments to identify all devices running affected versions of Openweave-core or Nest Cam IQ Indoor firmware, ensuring complete remediation across their network infrastructure. Additionally, the deployment of intrusion detection systems with protocol-aware inspection capabilities can help detect anomalous packet patterns that may indicate exploitation attempts. Organizations should also consider implementing network access controls that restrict communication between vulnerable devices and external networks, particularly in environments where these devices are used for surveillance or sensitive data collection. The vulnerability's classification as an information disclosure issue necessitates additional monitoring of system logs and network traffic for signs of data exfiltration or unauthorized access attempts, as the initial exploitation may be followed by further malicious activity. Regular security audits and vulnerability scanning should be implemented to ensure ongoing detection of similar integer overflow conditions that may exist in other components of the device's software stack, aligning with industry best practices for maintaining secure IoT device deployments.