CVE-2025-14956 identifies a heap-based buffer overflow vulnerability in the WebAssembly Binaryen project, version 125 and earlier. The vulnerability resides in the WasmBinaryReader::readExport function within the source file src/wasm/wasm-binary.cpp. This function improperly handles input data, leading to a heap overflow condition when processing WebAssembly export sections. The overflow can corrupt adjacent memory, potentially allowing an attacker to manipulate program behavior or cause a crash. Exploitation requires local access with limited privileges (PR:L) and does not require user interaction (UI:N). The attack complexity is low (AC:L), but the scope is limited to the local host environment. The CVSS 4.8 score reflects a medium severity, with partial impacts on confidentiality, integrity, and availability. The vulnerability has been publicly disclosed, and a patch identified by commit 4f52bff8c4075b5630422f902dd92a0af2c9f398 is available to remediate the issue. Binaryen is widely used as a compiler infrastructure for WebAssembly, often integrated into development tools and build systems. While no exploits are currently known in the wild, the public disclosure increases the risk of exploitation attempts. Organizations relying on Binaryen for WebAssembly processing should prioritize patching to prevent potential exploitation that could lead to denial of service or arbitrary code execution within the local environment.

The heap-based buffer overflow in Binaryen can lead to memory corruption, which may cause application crashes (denial of service) or potentially allow an attacker to execute arbitrary code with the privileges of the vulnerable process. Since exploitation requires local access with limited privileges, remote exploitation is not feasible without prior compromise. However, in multi-user or shared development environments, an attacker could leverage this vulnerability to escalate privileges or disrupt build pipelines. The impact on confidentiality is limited but possible if code execution is achieved. Integrity and availability impacts are more pronounced due to potential memory corruption and process instability. Organizations that use Binaryen in automated build systems or continuous integration environments could face operational disruptions. The medium severity rating suggests that while the vulnerability is not trivial, it warrants timely remediation to avoid exploitation risks, especially as the vulnerability is publicly disclosed.

1. Apply the official patch identified by commit 4f52bff8c4075b5630422f902dd92a0af2c9f398 immediately to all affected Binaryen installations. 2. Restrict local access to systems running Binaryen to trusted users only, minimizing the risk of local exploitation. 3. Implement strict access controls and monitoring on development and build servers where Binaryen is used. 4. Use sandboxing or containerization to isolate Binaryen processes, limiting the impact of potential exploitation. 5. Regularly update Binaryen and related WebAssembly toolchains to incorporate security fixes. 6. Conduct code audits and fuzz testing on WebAssembly processing components to detect similar vulnerabilities proactively. 7. Educate developers and system administrators about the risks of local privilege escalation vulnerabilities and best practices for secure development environments.