CVE-2019-9631
📋 TL;DR
CVE-2019-9631 is a heap-based buffer over-read vulnerability in Poppler's PDF rendering library. Attackers can exploit this by crafting malicious PDF files to cause denial of service or potentially execute arbitrary code. Systems using Poppler for PDF processing are affected, including document viewers, converters, and applications with PDF parsing functionality.
💻 Affected Systems
- Poppler
- Applications using Poppler library (e.g., Evince, Okular, PDF processing tools)
📦 What is this software?
Fedora by Fedoraproject
Fedora by Fedoraproject
Fedora by Fedoraproject
Poppler by Freedesktop
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Application crash causing denial of service, potentially leading to data loss or service disruption.
If Mitigated
Application crash with no privilege escalation if proper sandboxing and memory protections are enabled.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious PDF file. Public proof-of-concept code demonstrates crash/DoS.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Poppler 0.75.0 and later
Vendor Advisory: https://gitlab.freedesktop.org/poppler/poppler/issues/736
Restart Required: Yes
Instructions:
1. Update Poppler to version 0.75.0 or later. 2. Update all applications that use Poppler. 3. Restart affected services and applications.
🔧 Temporary Workarounds
Disable PDF processing
allTemporarily disable PDF processing in affected applications until patched.
Use alternative PDF renderer
allConfigure applications to use a different PDF rendering library that is not vulnerable.
🧯 If You Can't Patch
- Implement strict file upload filtering to block PDF files from untrusted sources.
- Deploy application sandboxing or containerization to limit impact of potential exploitation.
🔍 How to Verify
Check if Vulnerable:
Check Poppler version with: poppler-utils --version or dpkg -l | grep popplerCheck Version:
poppler-utils --version 2>/dev/null || dpkg -l | grep poppler || rpm -q popplerVerify Fix Applied:
Verify Poppler version is 0.75.0 or higher: poppler-utils --version | grep -q '0\.7[5-9]\|0\.[89]'📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults in Poppler/CairoRescaleBox
- Abnormal PDF processing errors
Network Indicators:
- Unusual PDF file downloads to servers with Poppler
- PDF uploads to web applications
SIEM Query:
source="application_logs" AND ("segmentation fault" OR "SIGSEGV") AND ("poppler" OR "CairoRescaleBox")🔗 References
- https://access.redhat.com/errata/RHSA-2019:2022
- https://access.redhat.com/errata/RHSA-2019:2713
- https://gitlab.freedesktop.org/poppler/poppler/issues/736
- https://lists.debian.org/debian-lts-announce/2019/04/msg00011.html
- https://lists.debian.org/debian-lts-announce/2020/07/msg00018.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6OSCOYM3AMFFBJWSBWY6VJVLNE5JD7YS/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ6RABASMSIMMWMDZTP6ZWUWZPTBSVB5/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZWP5XSUG6GNRI75NYKF53KIB2CZY6QQ6/
- https://usn.ubuntu.com/4042-1/
- https://access.redhat.com/errata/RHSA-2019:2022
- https://access.redhat.com/errata/RHSA-2019:2713
- https://gitlab.freedesktop.org/poppler/poppler/issues/736
- https://lists.debian.org/debian-lts-announce/2019/04/msg00011.html
- https://lists.debian.org/debian-lts-announce/2020/07/msg00018.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6OSCOYM3AMFFBJWSBWY6VJVLNE5JD7YS/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JQ6RABASMSIMMWMDZTP6ZWUWZPTBSVB5/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZWP5XSUG6GNRI75NYKF53KIB2CZY6QQ6/
- https://usn.ubuntu.com/4042-1/
