GHSA-r253-r9jw-qg44
CRITICALGHSA-r253-r9jw-qg44 is a critical-severity (CVSS 10) CWE-88 vulnerability in crawl4ai. O3 Security confirms whether GHSA-r253-r9jw-qg44 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Crawl4AI: Unauthenticated RCE via Chromium launch-argument injection in browser_config.extra_args
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-r253-r9jw-qg44.
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-r253-r9jw-qg44 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 372,324 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
crawl4aiReal-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 Docker API server accepted a request-supplied browser_config.extra_args, which flowed into Chromium's launch arguments. An attacker could inject Chromium switches that replace a child-process launch command (--utility-cmd-prefix, --renderer-cmd-prefix, --gpu-launcher, --browser-subprocess-path) together with --no-zygote, causing Chromium to fork/exec an attacker-controlled command as the container's runtime user. The Docker API is unauthenticated by default, so a single request yields arbitrary command execution.
The earlier extra_args SSRF patch (0.8.9) used a denylist scoped to proxy/DNS flags; a denylist of launch switches is inherently incomplete, and these command-execution switches were not covered.
Affected paths
/crawl, /crawl/stream, /crawl/job accepting a request browser_config.extra_args.
Impact
Unauthenticated remote code execution as the container runtime user; full read/write of application data, mounted secrets, environment, and tokens, and out-of-band exfiltration independent of the HTTP response.
Fix
0.9.0 establishes a trust boundary for request-supplied configuration: extra_args (along with other power fields such as proxy, user_data_dir, cdp_url, init_scripts) is a forbidden field for untrusted request bodies. Any request that sets extra_args is rejected with HTTP 400 rather than scrubbed against an always-incomplete denylist. In-process SDK callers (trusted) are unaffected.
Workarounds
- Upgrade to the patched version (0.9.0).
- Enable authentication (
CRAWL4AI_API_TOKEN) and restrict who can reach the API. - Run the container with a restrictive seccomp profile and no ability to exec helper binaries.
Credits
Y4tacker - reported the --no-zygote + --utility-cmd-prefix command-injection chain with a confirmed in-container PoC and an allowlist/reject recommendation.
UDU_RisePho (hoanggxyuuki) - independently reported the request-supplied Chromium launch-flag RCE class (--renderer-cmd-prefix), confirmed still reproducing on 0.8.9.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | crawl4ai | all versions | 0.9.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crawl4ai. 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 crawl4ai to 0.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r253-r9jw-qg44 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-r253-r9jw-qg44 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-r253-r9jw-qg44. 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-r253-r9jw-qg44 in your dependencies?
O3 detects GHSA-r253-r9jw-qg44 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.