dbcve.org
WasmtimeApplication · Bytecodealliance

CVE-2024-51745

CRITICAL · 10.0 CVSS v3.1 Published 2024-11-05
Fix available
A fix is available. Upgrade to 24.0.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Wasmtime is a fast and secure runtime for WebAssembly. Wasmtime's filesystem sandbox implementation on Windows blocks access to special device filenames such as "COM1", "COM2", "LPT0", "LPT1", and so on, however it did not block access to the special device filenames which use superscript digits, such as "COM¹", "COM²", "LPT⁰", "LPT¹", and so on. Untrusted Wasm programs that are given access to any filesystem directory could bypass the sandbox and access devices through those special device filenames with superscript digits, and through them gain access peripheral devices connected to the computer, or network resources mapped to those devices. This can include modems, printers, network printers, and any other device connected to a serial or parallel port, including emulated USB serial ports. Patch releases for Wasmtime have been issued as 24.0.2, 25.0.3, and 26.0.1. Users of Wasmtime 23.0.x and prior are recommended to upgrade to one of these patched versions. There are no known workarounds for this issue. Affected Windows users are recommended to upgrade.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Wasmtime's Windows filesystem sandbox fails to block access to special device filenames using Unicode superscript digits (COM¹, COM², LPT⁰, LPT¹), allowing untrusted WebAssembly programs to bypass the sandbox and access serial/parallel ports and connected peripherals including modems, printers, and emulated USB serial ports.

MitigationUpgrade Wasmtime to version 24.0.2, 25.0.3, or 26.0.1. No workarounds exist; affected Windows users must upgrade.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
WasmtimeApplication
Affected:< 24.0.2= 25.0.0= 25.0.1= 25.0.2= 26.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Wasmtime version
    Run `wasmtime --version` or check the version of the wasmtime library/binary in your deployment
    Affected if The version is less than 24.0.2, or equals 25.0.0, 25.0.1, 25.0.2, or 26.0.0
  2. Confirm operating system is Windows
    Verify the host system is running Windows, as this sandbox bypass applies only to Windows environments
    Affected if Wasmtime is running on Windows and the version is in the affected range
  3. Determine if filesystem sandboxing is enabled
    Review Wasmtime configuration for filesystem sandboxing settings, such as the `--dir` or `wasmtime::config::wasm::fs::Wasi` options used when spawning WebAssembly modules
    Affected if Filesystem sandboxing is configured and the Wasmtime version is vulnerable
  4. Test for superscript device filename access
    Attempt to open a file with a superscript digit in the name (for example, COM¹, COM², LPT⁰, or LPT¹) from an untrusted WebAssembly module running under the sandbox
    Affected if The sandbox permits access to these special device filenames on Windows

You are affected if Wasmtime versions 24.0.0-24.0.1, 25.0.0-25.0.2, or 26.0.0 are running on Windows with filesystem sandboxing enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 24.0.2 or later
Fixed in 24.0.2
Vendor patch github.com →
Interim mitigation

Upgrade Wasmtime to version 24.0.2, 25.0.3, or 26.0.1. No workarounds exist; affected Windows users must upgrade.

Recommended fix High confidence

Wasmtime 26.0.1 (or minimum 24.0.2 / 25.0.3)

  1. Identify the current installed version of Wasmtime using `wasmtime --version` or checking your dependency manager
  2. For package managers: update Wasmtime to version 26.0.1 (or 25.0.3 if 26.x is not compatible)
  3. For direct binary installation: download the appropriate Wasmtime release for your platform from the official GitHub releases page
  4. Verify the upgrade was successful by running `wasmtime --version` and confirming it shows 24.0.2, 25.0.3, or 26.0.1 or later
  5. Rebuild and redeploy any Wasm modules that depend on Wasmtime to ensure compatibility with the new version
  6. Test that Wasm modules function correctly with the updated runtime
Caveat Review Wasmtime changelog between your current version and target version for any breaking changes in API or behavior; minor version bumps typically have minimal breaking changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Wasmtime Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,790
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-51745 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data