CVE-2023-42451
Joinmastodon Mastodon ≤ 3.5.14
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-42451 is a high-severity Use of Incorrectly-Resolved Name or Reference (CWE-706) vulnerability in Joinmastodon Mastodon. Its CVSS base score is 7.4 (High).
Operationally, ranked in the top 49% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-46897
Vulnerability Data
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 3.5.14, 4.0.10, 4.1.8, and 4.2.0-rc2, under certain circumstances, attackers can exploit a flaw in domain name normalization to spoof domains they do not own. Versions 3.5.14,…
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4.0.10, 4.1.8, and 4.2.0-rc2 contain a patch for this issue.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Network segmentation and routing policies reduce the chance that a mis-resolved name leads to an unintended external resource.
Segregated networks limit the blast radius when a name or reference resolves outside the intended control sphere.
Secure SDLC practices include design reviews that can catch incorrect name or reference handling before deployment.
A.8.26 only requires that security requirements (including those that could address name-resolution issues) be identified during development or acquisition; it does not itself enforce, implement, or stop exploitation of an incorrectly-resolved name or reference.
A.8.27 mandates security-by-design principles (least privilege, default-deny, distrust-external-input, security-oriented design reviews, hardening) that reach many but not all name-resolution mistakes; a bounded remainder (e.g. flawed resolution logic inside trusted components or libraries) can still be introduced and exploited.
Secure-coding standards directly address canonicalization, input validation and safe name resolution, mitigating CWE-706.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-706, a class-level weakness, and none of its children carries one either.