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TI-2025-28437 Aliases CVE-2025-43853

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

Priority MEDIUM 64CWE-61Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · Low · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00293 22nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed wasm-micro-runtime (bytecodealliance): 2.3.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
bytecodealliancewasm-micro-runtimebefore 2.3.02.3.0Patch availableCNA
  • wasm-micro-runtime Vendorbytecodealliance Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:bytecodealliance:webassembly_micro_runtime:*:*:*:*:*:*:*:*before 2.2.0Vulnerablebytecodealliance
  • cpe:2.3:a:bytecodealliance:webassembly_micro_runtime:*:*:*:*:*:*:*:* Versions before 2.2.0 Vulnerable ·bytecodealliance

Remediation

  • Fix · CNA wasm-micro-runtime (bytecodealliance) Fixed in 2.3.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-43853

References

Exploit 1

Patch 1

  • TI-2024-16741 An issue in bytecodealliance wasm-micro-runtime before v.b3f728c and fixed in commit… CVSS 3.1HIGH 8.8
  • TI-2024-22658 An out-of-bound memory read vulnerability was discovered in Bytecode Alliance… CVSS 3.1HIGH 7.5
  • TI-2024-18300 wasm-micro-runtime (aka WebAssembly Micro Runtime or WAMR) 06df58f is vulnerable to NULL… CVSS 3.1HIGH 7.5
  • TI-2023-26034 An heap overflow vulnerability was discovered in Bytecode alliance wasm-micro-runtime… CVSS 3.1HIGH 7.5
  • TI-2025-33969 WebAssembly Micro Runtime's `--addr-pool` option allows all IPv4 addresses when subnet mask is not specified CVSS 4.0MEDIUM 6.9
  • TI-2024-22657 A heap buffer overflow vulnerability was discovered in Bytecode Alliance… CVSS 3.1MEDIUM 6.2
See all 10 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences