PT-2026-52867 · Pypi · Crawl4Ai

Published

2026-06-16

·

Updated

2026-06-16

CVSS v3.1

8.1

High

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

Three backward-compatible hardening fixes in the Docker API server. The headline issue is an arbitrary file write via the screenshot/PDF output path.

1. Arbitrary file write via output path symlink / TOCTOU (primary)

POST /screenshot and POST /pdf accept an output path constrained to ALLOWED OUTPUT DIR by validate output path. The 0.8.7 check was string-only: it did not resolve symlinks, so a symlinked path component inside the output directory could redirect the write outside the directory, and the final open() followed symlinks. On a deployment where the runtime user can write executable/cron locations this is an arbitrary-write to code-execution primitive. The API is unauthenticated by default.
Fix: validate output path now resolves the real path (symlinks) of the parent and re-checks containment, and the write uses O NOFOLLOW (write output file). output path remains supported.

2. CRLF log injection (CWE-117)

User-controlled URLs/errors reflected into log lines could embed CR/LF and forge additional log entries. Fix: a logging filter strips CR/LF/control characters from all records.

3. Webhook request-header injection (CWE-93/CWE-113)

User-supplied webhook headers were sent verbatim, allowing CRLF and hop-by-hop / sensitive header injection on the outbound webhook request. Fix: webhook headers are validated (name pattern, no control characters, deny Host/Content-Length/Transfer-Encoding/Authorization/Cookie/...), with early request-time rejection.

Impact

Arbitrary file write (potential code execution) for #1; log forging for #2; request smuggling / header injection on outbound webhooks for #3.

Workarounds

  • Upgrade to the patched version.
  • Enable authentication (CRAWL4AI API TOKEN).
  • Run the container with a read-only root filesystem.

Credits

Internal security audit (Crawl4AI maintainers).

Fix

Link Following

Path traversal

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Weakness Enumeration

CWE-59CWE-117CWE-22CWE-93

Related Identifiers

GHSA-7CX2-G3H9-382P

Affected Products

Crawl4Ai