CVE-2020-25464 in Moddable
Summary
by MITRE • 12/04/2020
Heap buffer overflow at moddable/xs/sources/xsDebug.c in Moddable SDK before before 20200903. The top stack frame is only partially initialized because the stack overflowed while creating the frame. This leads to a crash in the code sending the stack frame to the debugger.
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Analysis
by VulDB Data Team • 12/12/2020
The heap buffer overflow vulnerability CVE-2020-25464 resides within the Moddable SDK's debugging component at moddable/xs/sources/xsDebug.c, affecting versions prior to 20200903. This vulnerability represents a critical security flaw that manifests during the debugging process when the system attempts to handle stack frames. The issue stems from inadequate memory management during the creation of debug stack frames, where the top stack frame initialization process becomes compromised due to a heap overflow condition. The vulnerability specifically impacts the debugging functionality of the Moddable SDK, which is widely used for developing embedded applications and IoT solutions across various platforms including macOS, Windows, Linux, and mobile operating systems. This flaw occurs in the context of embedded development environments where debugging capabilities are essential for application development and testing phases.
The technical implementation of this vulnerability involves a classic heap buffer overflow scenario where memory allocated for stack frame data exceeds the boundaries of the allocated heap space. During the debugging process, when the system attempts to serialize and transmit stack frame information to a debugger client, the incomplete initialization of the top stack frame causes memory corruption. The overflow condition specifically affects the memory layout where the stack frame data is being constructed, leading to unpredictable behavior and system instability. This type of vulnerability falls under CWE-121, Heap-based Buffer Overflow, which is categorized as a memory safety issue in the Common Weakness Enumeration system. The vulnerability demonstrates characteristics consistent with CWE-787, Out-of-bounds Write, where the system writes data beyond the boundaries of allocated buffers. The flaw is particularly concerning because it occurs in a debugging context, meaning that any application utilizing the Moddable SDK's debugging features could be susceptible to exploitation during normal development operations.
The operational impact of CVE-2020-25464 extends beyond simple system crashes, representing a potential vector for more sophisticated attacks within development environments. When exploited, this vulnerability can cause denial of service conditions that disrupt development workflows and potentially provide attackers with opportunities to escalate privileges or gain unauthorized access to development systems. The crash behavior manifests specifically when the debugging system attempts to transmit corrupted stack frame data to external debugger clients, which could be exploited by malicious actors to cause system instability or potentially execute arbitrary code. The vulnerability affects a wide range of embedded development scenarios where Moddable SDK is utilized, including smart home devices, industrial IoT applications, and mobile applications that leverage the SDK's cross-platform capabilities. This makes the impact particularly severe for organizations that rely on embedded systems development and deployment in critical infrastructure environments. According to ATT&CK framework, this vulnerability could be leveraged as part of a broader attack chain under techniques such as T1059.007, Command and Scripting Interpreter: JavaScript, when targeting development environments where JavaScript-based embedded applications are created and debugged.
Mitigation strategies for CVE-2020-25464 primarily focus on immediate version updates to Moddable SDK 20200903 or later, which contains the necessary patches to address the heap buffer overflow condition. Organizations should implement comprehensive vulnerability management processes that include regular updates to development tools and SDKs, particularly those used in embedded systems development. The patch addresses the root cause by ensuring proper memory allocation and initialization of stack frame data structures during debugging operations, preventing the overflow condition from occurring. Additional defensive measures include implementing runtime monitoring for heap corruption detection, restricting debugging access to trusted development environments, and conducting regular security assessments of development infrastructure. Security teams should also consider implementing network segmentation for development environments to limit potential attack vectors and ensure that debugging systems are not exposed to untrusted networks. The vulnerability highlights the importance of secure coding practices in development toolchains and emphasizes the need for regular security audits of embedded development frameworks, particularly those used in IoT and embedded systems where security vulnerabilities can have far-reaching consequences. Organizations should also establish processes for monitoring and responding to security advisories related to development tools and SDKs to maintain secure development practices.