pypdf: Possible long runtimes for large xref table header limits

Summary

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an attacker can craft a PDF with a standard cross-reference table whose declared entry count exceeds what the file can contain, causing excessive processing and long runtimes when the file is opened. This issue is fixed in version 6.21.2.

Remediation

1. Inventory every py-pdf pypdf deployment, including staging.
2. No fixed version appears in the public sources yet. Check the references below and the vendor directly.

References

• Referencehttps://github.com/py-pdf/pypdf/commit/a3061e34b169d34478d520f5f049c53cfb1482b2
• Referencehttps://github.com/py-pdf/pypdf/pull/4239
• Referencehttps://github.com/py-pdf/pypdf/releases/tag/6.21.2
• Referencehttps://github.com/py-pdf/pypdf/security/advisories/GHSA-gmh7-3g9r-mjh5