PyPDF2 quadratic runtime with malformed PDF missing xref marker

Impact

An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime.
This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.

Patches

https://github.com/py-pdf/pypdf/pull/808

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

References

• PyPDF2 PR #808
• PyPDF2 Issue #582