CVE-2019-7704 in Binaryen
Summary
by MITRE
wasm::WasmBinaryBuilder::readUserSection in wasm-binary.cpp in Binaryen 1.38.22 triggers an attempt at excessive memory allocation, as demonstrated by wasm-merge and wasm-opt.
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Analysis
by VulDB Data Team • 07/09/2023
The vulnerability identified as CVE-2019-7704 resides within the Binaryen compiler toolchain version 1.38.22, specifically in the wasm::WasmBinaryBuilder::readUserSection function located in wasm-binary.cpp. This flaw represents a critical memory allocation issue that can be exploited through malicious WebAssembly binary files, making it particularly dangerous in environments where untrusted wasm content is processed. The vulnerability manifests when the readUserSection function attempts to allocate excessive memory resources during the parsing of user-defined sections within WebAssembly modules, creating a potential denial of service condition that could be leveraged by attackers to consume system resources.
The technical implementation of this vulnerability stems from inadequate input validation and memory allocation controls within the WebAssembly binary parsing logic. When Binaryen processes WebAssembly files containing specially crafted user sections, the wasm::WasmBinaryBuilder::readUserSection function fails to properly validate the size parameters of these sections before attempting allocation. This allows an attacker to craft malicious WebAssembly binaries that request impossibly large memory allocations, potentially leading to system resource exhaustion or process termination. The issue affects both wasm-merge and wasm-opt tools, which are commonly used for WebAssembly module manipulation and optimization, making the vulnerability exploitable in various development and deployment scenarios.
The operational impact of CVE-2019-7704 extends beyond simple denial of service conditions, as it can be leveraged to disrupt services that depend on Binaryen for WebAssembly processing. Systems utilizing these tools for code analysis, optimization, or deployment may experience complete service interruption when processing malicious inputs, potentially affecting web applications, serverless functions, or development environments. The vulnerability is particularly concerning in cloud environments where WebAssembly processing is common, as it can be used to exhaust memory resources and impact other running processes on the same system. This represents a significant concern for organizations relying on automated build pipelines or continuous integration systems that utilize Binaryen tools.
Security mitigations for this vulnerability should focus on input validation and resource limiting measures. Organizations should upgrade to Binaryen versions that have patched this vulnerability, as version 1.38.23 and later contain the necessary fixes. Additionally, implementing strict memory limits and resource controls when executing wasm-merge and wasm-opt commands can help prevent exploitation. The vulnerability aligns with CWE-770, which addresses allocation of resources without limits or with inadequate limits, and can be categorized under ATT&CK technique T1499.001 for resource exhaustion attacks. System administrators should also consider implementing sandboxing mechanisms and input sanitization for any WebAssembly processing pipelines to reduce the attack surface and prevent unauthorized memory allocation attempts.