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GHSA-r253-r9jw-qg44
No affected components available
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.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.
Active exploitation in the wild has been confirmed. Immediate patching or mitigation is required.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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