CVE-2024-46657

What it actually does

The flaw triggers a segmentation fault in the pdfextract component when parsing a maliciously crafted PDF, causing the process to crash and resulting in denial of service.

Why it matters to the business

Organizations relying on MuPDF for PDF extraction or processing may experience sudden application crashes and workflow interruptions when handling untrusted documents.

How an attack unfolds

An attacker prepares a specially crafted PDF that exercises the vulnerable code path in pdfextract.c and supplies the file to any application or service that invokes the affected MuPDF tool, leading to an immediate crash.

How to fix it

Update affected MuPDF installations to a version newer than 1.24.9. For the listed Ubuntu Pro 16.04 LTS packages, apply the fixed release 2:1.7.6-1ubuntu0.1~esm1.

How to confirm the fix worked

Confirm the installed MuPDF version exceeds 1.24.9, then re-test pdfextract against known trigger PDFs to verify absence of the crash.

Typical attack path

1. Locate a target service or workflow that invokes MuPDF pdfextract on user-supplied PDFs
2. Generate a malformed PDF that triggers the segmentation fault
3. Deliver the crafted file through normal input channels
4. Observe the resulting process crash and service denial

How to detect it

Review application and system logs for segmentation fault entries or abrupt process terminations immediately following PDF extraction attempts; correlate with file ingestion timestamps.

What your security team should do

• Prioritize patching MuPDF in all environments that accept untrusted PDFs
• Restrict pdfextract usage to trusted input sources until updates are deployed
• Monitor application logs for unexpected segmentation faults during PDF handling