Fedify has an incomplete SSRF mitigation after GHSA-p9cg-vqcc-grcx: validatePublicUrl allows special-use IPv4 ranges
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 1.9.12, 1.10.11, 2.0.19, 2.1.15, 2.2.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 1 proof of concept on GitHub
- Exploitation: poc
- Automatable: yes
- Technical impact: partial
Summary
Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Fedify previously addressed SSRF/internal network access in GHSA-p9cg-vqcc-grcx by adding public URL validation before runtime document and media fetching. However, the IPv4 validation logic present starting in version 0.11.2 and prior to versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 appears incomplete. The `validatePublicUrl()` protection relies on `isValidPublicIPv4Address()` to reject non-public IPv4 destinations. The function blocks common private and local ranges such as `10.0.0.0/8`, `127.0.0.0/8`, `169.254.0.0/16`, `172.16.0.0/12`, and `192.168.0.0/16`, but it still treats several special-use, reserved, multicast, benchmarking, and carrier-grade NAT IPv4 ranges as valid public destinations. Because this validation is used as an SSRF defense before outbound fetches, this appears to be an incomplete mitigation or bypass class for the previous SSRF issue. Versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 contain an updated patch.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- fedify-dev fedify
From 0.11.2 · fixed in 1.9.12; From 1.10.0 · fixed in 1.10.11; From 2.0.0 · fixed in 2.0.19; From 2.1.0 · fixed in 2.1.15; From 2.2.0 · fixed in 2.2.4
- fedify-dev vocab-runtime
fixed in 2.0.19; From 2.1.0 · fixed in 2.1.15; From 2.2.0 · fixed in 2.2.4
- @fedify/fedifynpm
From 0.11.2 · fixed in 1.9.12
- @fedify/fedifynpm
From 1.10.0 · fixed in 1.10.11
- @fedify/fedifynpm
From 2.0.0 · fixed in 2.0.19
- @fedify/fedifynpm
From 2.1.0 · fixed in 2.1.15
- @fedify/fedifynpm
From 2.2.0 · fixed in 2.2.4
- @fedify/vocab-runtimenpm
fixed in 2.0.19
- @fedify/vocab-runtimenpm
From 2.1.0 · fixed in 2.1.15
- @fedify/vocab-runtimenpm
From 2.2.0 · fixed in 2.2.4