CVE-2025-43853

iwasm vulnerable to filesystem sandbox escape with symlink when using uvwasi feature

Description

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.

Category

7.0
CVSS
Severity: High
CVSS 4.0 •
EPSS 0.02%
Affected: bytecodealliance wasm-micro-runtime
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2025-43853?
CVE-2025-43853 has been scored as a high severity vulnerability.
How to fix CVE-2025-43853?
To fix CVE-2025-43853, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-43853 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-43853 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-43853?
CVE-2025-43853 affects bytecodealliance wasm-micro-runtime.
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