CVE-2019-7151 in Binaryen
Summary
by MITRE
A NULL pointer dereference was discovered in wasm::Module::getFunctionOrNull in wasm/wasm.cpp in Binaryen 1.38.22. A crafted input can cause segmentation faults, leading to denial-of-service, as demonstrated by wasm-opt.
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Analysis
by VulDB Data Team • 07/03/2023
The vulnerability identified as CVE-2019-7151 represents a critical null pointer dereference flaw within the Binaryen web assembly toolchain version 1.38.22. This issue resides in the wasm::Module::getFunctionOrNull function located in the wasm/wasm.cpp file, which forms a core component of the Binaryen compiler infrastructure used for processing and optimizing web assembly modules. The flaw manifests when the system encounters malformed or crafted input during the processing of web assembly files, specifically in the context of the wasm-opt utility which serves as a command-line tool for optimizing web assembly binaries. The vulnerability operates at the intersection of software robustness and memory management, where proper input validation fails to prevent execution paths that lead to dereferencing null pointers.
The technical exploitation of this vulnerability occurs when an attacker provides maliciously constructed web assembly input that triggers the getFunctionOrNull method to attempt accessing a null pointer reference. This particular flaw falls under the CWE-476 category of NULL Pointer Dereference, which represents a well-known class of software vulnerabilities that occur when an application attempts to access a memory location through a pointer that has not been properly initialized to point to a valid memory address. The attack vector specifically targets the wasm-opt utility's handling of function lookups within web assembly modules, where the absence of proper null checks in the getFunctionOrNull method creates an execution path that results in segmentation faults when the application attempts to dereference the null pointer.
The operational impact of this vulnerability extends beyond simple denial-of-service conditions, as it can be leveraged to crash the wasm-opt utility and potentially other applications that utilize the affected Binaryen library. This creates significant risks for development environments, continuous integration systems, and automated build processes that rely on web assembly optimization tools. When exploited, the vulnerability results in segmentation faults that terminate the target process, effectively preventing legitimate web assembly compilation and optimization workflows from completing successfully. The vulnerability affects the broader web assembly ecosystem since Binaryen serves as a foundational tool for web assembly development and optimization, making it a potential attack surface for adversaries seeking to disrupt development processes or gain unauthorized access through system compromise.
Mitigation strategies for CVE-2019-7151 should prioritize immediate patching of affected Binaryen versions to 1.38.23 or later, where the null pointer dereference has been addressed through proper input validation and null pointer checks. Organizations should implement comprehensive input sanitization procedures for all web assembly files processed through Binaryen tools, particularly in automated environments where untrusted input may be encountered. Additionally, deployment of runtime monitoring and intrusion detection systems can help identify exploitation attempts by monitoring for abnormal process termination patterns. The vulnerability aligns with ATT&CK technique T1499.004 for network denial-of-service attacks, where system availability is compromised through targeted exploitation of software flaws. Security teams should also consider implementing sandboxing mechanisms for web assembly processing environments to limit the potential impact of successful exploitation attempts, ensuring that even if the vulnerability is exploited, the broader system remains protected from cascading failures.