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CVE

CVE-2023-42450

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services.

Version 4.2.0-rc2 has a patch for the issue.

MEDIUM · CVSS 5.4 EPSS 0.00376
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
CWE-918Server-Side Request Forgery (SSRF)
▤

Affected Products & Versions

1
joinmastodon mastodonall versions
▣

Scoring & Timeline

5.4
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD19 Sep 2023 · 04:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/mastodon/mastodon/commit/94893cf24fc95b32cc7a756262acbe008c20a9d2Patch
https://github.com/mastodon/mastodon/security/advisories/GHSA-hcqf-fw2r-52g4Vendor Advisory
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