CVE-2023-31669Public exploit

Converter crash via invalid annotation offset

Published May 23, 2023 · Updated Jan 31, 2025

Denial of service in WebAssembly WABT wat2wasm 1.0.32 allows local users to crash the converter by processing a crafted WAT file. WastLexer::GetText receives an offset earlier than token_start after GetStringToken resets token_start at a newline, causing an uncaught std::length_error. A user must invoke wat2wasm on input containing an annotation marker immediately before an unterminated quote; the consequence is termination of that converter process.

CVSS severity5.5
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in WebAssembly WABT wat2wasm 1.0.32 allows local users to crash the converter by processing a crafted WAT file. WastLexer::GetText receives an offset earlier than token_start after GetStringToken resets token_start at a newline, causing an uncaught std::length_error. A user must invoke wat2wasm on input containing an annotation marker immediately before an unterminated quote; the consequence is termination of that converter process.

The record

CVE
CVE-2023-31669
Published
May 23, 2023
Updated
Jan 31, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-116, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 31, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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