[PDFBOX-5401] A carefully crafted pdf can trigger an infinite loop while parsing

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0 PDFBox
• Fix Version/s: 2.0.26, 3.0.0 PDFBox
• Component/s: Parsing, PDModel
• Environment: Mac OS 12.1 & Ubuntu Linux 16.04 (4.15.0-163-generic)
• Assignee: Andreas Lehmkühler
• Reporter: Xiaohan Zhang
• Created: 25/Mar/22 12:52
• Updated: 21/Apr/22 15:38
• Resolved: 28/Mar/22 06:22

Description

Hi, I found a crafted pdf that can trigger an infinite loop while parsing using PDFBOX. I have tested on the latest commit of PDFBOX on Github.

 

This bug can be triggered by the following code.

```

File ff = new File("path/to/the/sample");

PDDocument document = Loader.loadPDF(ff);

```

 

I found that the root cause of this infinite loop resides in the while-loop at line 321 of  COSParse.java.]. When parsing the provided PDF files, the variable $prev is never changed during this loop.