CVE-2022-31169 : Exploit Details and Defense Strategies

Cranelift, the code generator used by Wasmtime for AArch64 targets, has a bug that causes incorrect division results at runtime due to constant divisors. This CVE affects Wasmtime versions prior to 0.38.2 and Cranelift versions prior to 0.85.2 specifically on the AArch64 platform. The bug has a medium severity score of 5.9 CVSS V3.1 and is classified under CWE-682: Incorrect Calculation.

Understanding CVE-2022-31169

This section covers the impact, technical details, and mitigation strategies related to CVE-2022-31169.

What is CVE-2022-31169?

CVE-2022-31169 highlights a vulnerability in Wasmtime's code generator, Cranelift, where constant divisors lead to incorrect division outcomes on AArch64 architectures, potentially causing WebAssembly programs to deviate from the expected behavior.

The Impact of CVE-2022-31169

The vulnerability has the potential to disrupt the execution of WebAssembly programs within the sandbox, resulting in unexpected behaviors. While it may not affect hosts executing WebAssembly, guest programs' correctness can be compromised.

Technical Details of CVE-2022-31169

This section delves deeper into the technical aspects of the CVE.

Vulnerability Description

The bug occurs due to inaccurate translation rules for constants, overlooking sign or zero-extension considerations, leading to erroneous values when processing divisions.

Affected Systems and Versions

Wasmtime versions prior to 0.38.2 and Cranelift versions prior to 0.85.2 on the AArch64 architecture are impacted by this vulnerability.

Exploitation Mechanism

Inappropriate handling of constant divisors during code generation for AArch64 targets in Wasmtime's Cranelift can result in miscompiled code affecting the correct execution of WebAssembly programs.

Mitigation and Prevention

Discover the necessary steps to mitigate the risks posed by CVE-2022-31169.

Immediate Steps to Take

Ensure the timely update of Wasmtime to version 0.38.2 and Cranelift to version 0.85.2 to patch the vulnerability and prevent miscompilation of constant divisors on AArch64 platforms.

Long-Term Security Practices

Implement regular security audits and updates to address potential vulnerabilities and secure the execution environment of WebAssembly programs.

Patching and Updates

Stay informed about security advisories and apply patches promptly to stay protected from emerging threats.