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CVE-2025-67500

Mastodon Error Handling Discrepancy Enables Private Status Existence Enumeration

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 4.2.28, 4.3.15, 4.4.10, 4.5.3
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

Mastodon is a free, open-source social network server based on ActivityPub. Versions 4.2.27 and prior, 4.3.0-beta.1 through 4.3.14, 4.4.0-beta.1 through 4.4.9, 4.5.0-beta.1 through 4.5.2 have discrepancies in error handling which allow checking whether a given status exists by sending a request with a non-English Accept-Language header. Using this behavior, an attacker who knows the identifier of a particular status they are not allowed to see can confirm whether this status exists or not. This cannot be used to learn the contents of the status or any other property besides its existence. This issue is fixed in versions 4.2.28, 4.3.15, 4.4.10 and 4.5.3.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • mastodon mastodon

    fixed in 4.2.28; From 4.3.0-beta.1 · fixed in 4.3.15; From 4.4.0-beta.1 · fixed in 4.4.10; From 4.5.0-beta.1 · fixed in 4.5.3

References 2

GitHub · mastodon/mastodon