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.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 19 Sep 2025 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Bytecodealliance
Bytecodealliance webassembly Micro Runtime
CPEs cpe:2.3:a:bytecodealliance:webassembly_micro_runtime:*:*:*:*:*:*:*:*
Vendors & Products Bytecodealliance
Bytecodealliance webassembly Micro Runtime
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}


Thu, 15 May 2025 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 15 May 2025 17:30:00 +0000

Type Values Removed Values Added
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.
Title iwasm vulnerable to filesystem sandbox escape with symlink when using uvwasi feature
Weaknesses CWE-61
References
Metrics cvssV4_0

{'score': 7, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-05-15T18:05:18.829Z

Reserved: 2025-04-17T20:07:08.555Z

Link: CVE-2025-43853

cve-icon Vulnrichment

Updated: 2025-05-15T18:05:07.992Z

cve-icon NVD

Status : Analyzed

Published: 2025-05-15T18:15:37.760

Modified: 2025-09-19T18:10:45.997

Link: CVE-2025-43853

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.