MEDIUM CVSS 5.9
Published: 2022-11-10

CVE-2022-39392

bytecodealliance wasmtime Security Advisory (CVE-2022-39392)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2022-39392?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2022-39392 impacting bytecodealliance wasmtime. Evaluated with CVSS Base Score of 5.9 (MEDIUM).

Original NVD Description

Source: NIST NVD
Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator when the allocator is configured to give WebAssembly instances a maximum of zero pages of memory. In this configuration, the virtual memory mapping for WebAssembly memories did not meet the compiler-required configuration requirements for safely executing WebAssembly modules. Wasmtime's default settings require virtual memory page faults to indicate that wasm reads/writes are out-of-bounds, but the pooling allocator's configuration would not create an appropriate virtual memory mapping for this meaning out of bounds reads/writes can successfully read/write memory unrelated to the wasm sandbox within range of the base address of the memory mapping created by the pooling allocator. This bug is not applicable with the default settings of the `wasmtime` crate. This bug can only be triggered by setting `InstanceLimits::memory_pages` to zero. This is expected to be a very rare configuration since this means that wasm modules cannot allocate any pages of linear memory. All wasm modules produced by all current toolchains are highly likely to use linear memory, so it's expected to be unlikely that this configuration is set to zero by any production embedding of Wasmtime. This bug has been patched and users should upgrade to Wasmtime 2.0.2. This bug can be worked around by increasing the `memory_pages` allotment when configuring the pooling allocator to a value greater than zero. If an embedding wishes to still prevent memory from actually being used then the `Store::limiter` method can be used to dynamically disallow growth of memory beyond 0 bytes large. Note that the default `memory_pages` value is greater than zero.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
High (PR:H)
Administrative credentials required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product bytecodealliance / wasmtime
Affected Versions *
Weakness Enumeration CWE-119

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2022-39392 impacting bytecodealliance wasmtime.

⚡ Nuclei Detection Template (YAML) cve-2022-39392.yaml
id: cve-2022-39392

info:
  name: bytecodealliance wasmtime - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2022-39392 affecting bytecodealliance wasmtime.
    Evaluation: Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's implementation of its pooling instance all...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2022-39392
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
    cvss-score: 5.9
    cve-id: CVE-2022-39392
    cwe-id: CWE-119
  tags: cve,cve-2022-39392,bytecodealliance,wasmtime,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "wasmtime"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2022-39392.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2022-39392
# Target: bytecodealliance wasmtime | CVSS: 5.9 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2022-39392 (bytecodealliance wasmtime)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against bytecodealliance wasmtime scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2022-39392.sh
# Recommended Remediation & Patching Commands for CVE-2022-39392
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install wasmtime 2>/dev/null || \
sudo dnf upgrade wasmtime 2>/dev/null || \
sudo yum update wasmtime

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i wasmtime 2>/dev/null || rpm -qa | grep -i wasmtime

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2022-39392 in bytecodealliance wasmtime?

Review vendor-specific security notices and update bytecodealliance wasmtime packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2022-39392?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2022-39392?

CVE-2022-39392 is classified with a CVSS 3.1 Base Score of 5.9 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.9
MEDIUM SEVERITY
CVE ID CVE-2022-39392
Weakness CWE-119
Vendor bytecodealliance
Product wasmtime
Published 2022-11-10
Vector CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N