CVE-2025-43853 HIGH

CVE-2025-43853: iwasm vulnerable to filesystem sandbox escape with symlink when using uvwasi feature

Vendor Bytecodealliance
Product wasm-micro-runtime
Weakness CWE-61
Published May 15, 2025
Last update May 15, 2025

CVSS base score

7.0/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface (WASI) and command line interface. Anyone running WAMR up to and including version 2.2.0 or WAMR built with libc-uvwasi on Windows is affected by a symlink following vulnerability. On WAMR running in Windows, creating a symlink pointing outside of the preopened directory and subsequently opening it with create flag will create a file on host outside of the sandbox. If the symlink points to an existing host file, it's also possible to open it and read its content. Version 2.3.0 fixes the issue.

Key dates

02Disclosure timeline

May 15, 2025 CVE published
May 15, 2025 Record updated