CVE-2019-15758 in Binaryen
Summary
by MITRE
An issue was discovered in Binaryen 1.38.32. Missing validation rules in asmjs/asmangle.cpp can lead to an Assertion Failure at wasm/wasm.cpp in wasm::asmangle. A crafted input can cause denial-of-service, as demonstrated by wasm2js.
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Analysis
by VulDB Data Team • 12/07/2023
The vulnerability identified as CVE-2019-15758 resides within the Binaryen web assembly toolchain version 1.38.32, specifically affecting the asmjs/asmangle.cpp component where insufficient validation mechanisms exist. This flaw manifests as an assertion failure in the wasm/wasm.cpp file during wasm::asmangle operations, creating a potential denial-of-service condition that can be triggered through carefully crafted inputs. The vulnerability is particularly concerning because it affects the wasm2js conversion tool which serves as a bridge between web assembly and javascript environments, making it a critical component in web assembly processing pipelines.
The technical root cause stems from inadequate input validation within the asmangle functionality that handles assembly language mangling operations. When processing malformed or specially constructed asm.js inputs, the system fails to properly validate the input parameters before proceeding with the mangling process. This validation gap allows an attacker to craft inputs that cause the assertion to fail, resulting in a program termination that disrupts normal operation. The flaw demonstrates characteristics consistent with CWE-20, which addresses improper input validation, and represents a classic example of how insufficient boundary checking can lead to system instability. The vulnerability specifically impacts the wasm::asmangle function which is responsible for converting between different web assembly representations, making it a fundamental component in the web assembly compilation pipeline.
The operational impact of this vulnerability extends beyond simple denial-of-service conditions, as it can potentially disrupt web assembly processing workflows in applications that rely on Binaryen for compilation and conversion tasks. When exploited, the assertion failure can cause complete termination of the wasm2js tool, preventing legitimate web assembly conversions from completing successfully. This disruption affects not only individual development environments but also automated build systems and continuous integration pipelines that depend on reliable web assembly tooling. The vulnerability's exploitation requires minimal complexity since it only requires crafting specific input patterns that trigger the validation gap, making it accessible to attackers with basic knowledge of web assembly formats and the Binaryen toolchain architecture. Organizations using Binaryen in production environments face potential service interruptions and workflow disruptions when this vulnerability is successfully exploited.
Mitigation strategies for CVE-2019-15758 primarily involve upgrading to a patched version of Binaryen where the validation rules have been properly implemented in asmjs/asmangle.cpp. System administrators should also consider implementing input sanitization measures at the boundary of web assembly processing workflows to prevent malformed inputs from reaching the vulnerable components. Additionally, organizations should conduct regular security assessments of their web assembly toolchains to identify similar validation gaps that may exist in other components. The vulnerability aligns with ATT&CK technique T1499.004 which covers network denial-of-service attacks, and organizations should ensure their incident response procedures account for potential service disruptions caused by such validation failures. Monitoring for assertion failures in web assembly processing environments and implementing proper error handling for malformed inputs can help detect potential exploitation attempts. Regular updates to the Binaryen toolchain and comprehensive testing of web assembly conversion workflows should be part of standard security practices to prevent similar vulnerabilities from compromising system availability.