Server‑Side Request Forgery in flyto_core 2.26.7 Enables Internal Service Access via DNS‑Rebinding
What Happened – A validation routine in flyto_core ≤ 2.26.7 (validate_url_ssrf) checks the first DNS resolution of a URL but then reconnects after a second resolution without pinning the IP address. An attacker can use a TTL‑0 DNS‑rebinding trick to force the second lookup to resolve to an internal address, bypassing the guard and reaching private services. The flaw is documented in an Exploit‑DB entry (EDB‑ID 52651) and a GitHub Security Advisory (GHSA‑6pm8‑6f34‑9v3g).
Why It Matters for Compliance & Audit Readiness
- Demonstrates a classic application‑level control gap that SOC 2 CC6.1 (System Operations) and CC7.1 (Change Management) expect organizations to identify, remediate, and continuously monitor.
- Provides concrete evidence for a “secure development lifecycle” control (CC6.2) – the need for automated code‑review and vulnerability‑scanning pipelines that surface SSRF‑type defects before release.
- Aligns with Verisq’s Control Mapping capability: map the SSRF finding to the relevant SOC 2 controls, collect continuous evidence of remediation, and store proof in the Trust Center for audit reviewers.
Who Is Affected – SaaS platforms, internal developer portals, and any organization that incorporates the open‑source flyto_core library in production web applications.
Recommended Actions
- Upgrade to flyto_core 2.26.8 or later immediately.
- Add IP‑pinning or double‑resolution verification to any URL‑fetch logic; treat DNS‑rebinding as a high‑risk vector in threat‑modeling.
- Incorporate SSRF test cases into CI/CD pipelines and map the remediation to SOC 2 CC6.1/CC6.2 controls.
- Document the change and retain evidence (patch version, test logs) in a continuous‑compliance repository.
Source: Exploit‑DB 52651
Technical Notes – The vulnerability is a logic flaw (no CVE) that allows an attacker to bypass validate_url_ssrf via DNS‑rebinding (TTL = 0). No network‑wide payload is delivered in the PoC, but the technique can be leveraged to reach internal APIs, metadata services, or cloud‑provider endpoints.