CVE-2021-29323 in OpenSource
Summary
by MITRE • 11/19/2021
OpenSource Moddable v10.5.0 was discovered to contain a heap buffer overflow via the component /modules/network/wifi/esp/modwifi.c.
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Analysis
by VulDB Data Team • 11/22/2021
The heap buffer overflow vulnerability in OpenSource Moddable v10.5.0 represents a critical security flaw within the wireless network component of this embedded development platform. This vulnerability specifically affects the modwifi.c file located in the /modules/network/wifi/esp/ directory, indicating that it is part of the ESP32 wireless networking implementation within the Moddable runtime environment. The issue manifests as a heap buffer overflow, which occurs when a program writes more data to a heap-allocated buffer than it can accommodate, potentially leading to memory corruption and arbitrary code execution.
The technical nature of this vulnerability stems from improper input validation and memory management within the wireless network module. When the ESP32 wireless functionality processes network packets or configuration data, it fails to properly bounds-check buffer operations, allowing attackers to craft malicious inputs that exceed allocated buffer boundaries. This type of vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions, though the heap-based variant presents similar exploitation risks. The heap buffer overflow can result in memory corruption that may be exploited to overwrite adjacent memory locations, potentially leading to privilege escalation or remote code execution within the context of the Moddable runtime environment.
The operational impact of this vulnerability extends beyond simple memory corruption, as it affects embedded systems and IoT devices that rely on Moddable for wireless connectivity. Attackers could potentially exploit this vulnerability by sending malformed wireless network data or configuration parameters to devices running Moddable v10.5.0, particularly those using ESP32 microcontrollers. This creates a significant risk for IoT deployments where these devices may be exposed to untrusted network environments, as the vulnerability could be leveraged to gain unauthorized access to the device or compromise the entire network infrastructure. The attack surface is particularly concerning given that Moddable is used in embedded applications where devices may operate in sensitive environments without traditional security controls.
Mitigation strategies for this vulnerability should prioritize immediate patching of the Moddable runtime to version v10.5.1 or later, which contains the necessary fixes for the heap buffer overflow. Organizations should implement network segmentation and access controls to limit exposure of affected devices to untrusted networks, following ATT&CK technique T1046 for network service scanning and T1071 for application layer protocols. Additionally, input validation should be strengthened at multiple layers, including network protocol parsing and configuration parameter handling, to prevent malformed data from reaching the vulnerable code paths. Regular security assessments of embedded systems and network monitoring should be implemented to detect potential exploitation attempts, while maintaining up-to-date threat intelligence regarding similar vulnerabilities in embedded systems and IoT platforms.