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Infinite loop vulnerability in ASF parser

High
Borewit published GHSA-v6c2-xwv6-8xf7 Mar 17, 2026

Package

npm music-metadata (npm)

Affected versions

<11.12.1

Patched versions

11.12.3

Description

Summary

music-metadata's ASF parser (parseExtensionObject() in lib/asf/AsfParser.ts:112-158) enters an infinite loop when a sub-object inside the ASF Header Extension Object has objectSize = 0.

Root Cause

When objectSize is 0:

  1. remaining = 0 - 24 = -24
  2. tokenizer.ignore(-24) moves the read position backward by 24 bytes
  3. extensionSize -= 0 (loop counter never decreases)
  4. while (extensionSize > 0) never exits
  5. The same 24-byte header is re-read infinitely

This is the same pattern as CVE-2026-31808 (GHSA-5v7r-6r5c-r473) in file-type — strtok3's AbstractTokenizer.ignore() accepts negative values without validation.

Affected Methods

  • parseFile() — HANGS (FileTokenizer inherits vulnerable ignore())
  • parseBuffer() — HANGS (BufferTokenizer inherits vulnerable ignore())
  • parseStream() — NOT affected (ReadStreamTokenizer has own ignore() that throws RangeError)

Impact

A 100-byte crafted .asf file permanently hangs any application using parseFile() or parseBuffer(). music-metadata has 2.2M weekly npm downloads.

Suggested Fix

Validate objectSize >= minimumHeaderSize before calculating the payload. Or fix strtok3's AbstractTokenizer.ignore() to reject negative values.

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2026-32256

Weaknesses

Loop with Unreachable Exit Condition ('Infinite Loop')

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. Learn more on MITRE.

Credits