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CVE-2026-31808GHSA-5V7R-6R5C-R473

file-type affected by infinite loop in ASF parser on malformed input with zero-size sub-header

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 21.3.1
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

file-type detects the file type of a file, stream, or data. Prior to 21.3.1, a denial of service vulnerability exists in the ASF (WMV/WMA) file type detection parser. When parsing a crafted input where an ASF sub-header has a size field of zero, the parser enters an infinite loop. The payload value becomes negative (-24), causing tokenizer.ignore(payload) to move the read position backwards, so the same sub-header is read repeatedly forever. Any application that uses file-type to detect the type of untrusted/attacker-controlled input is affected. An attacker can stall the Node.js event loop with a 55-byte payload. Fixed in version 21.3.1.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • sindresorhus file-type

    From 13.0.0 · fixed in 21.3.1

  • file-typenpm

    From 13.0.0 · fixed in 21.3.1

References 2

GitHub · sindresorhus/file-type