CVE-2024-28109
📋 TL;DR
CVE-2024-28109 is a remote code execution vulnerability in veraPDF-library that allows attackers to execute arbitrary code by exploiting XSL transformations during custom Schematron policy checks. This affects systems using veraPDF-library for PDF/A validation with custom policy files. The vulnerability is particularly dangerous because it can be triggered through malicious PDF files or policy configurations.
💻 Affected Systems
- veraPDF-library
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to execute arbitrary commands with the privileges of the veraPDF process, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Remote code execution leading to data exfiltration, installation of backdoors, or use of the compromised system as a foothold for further attacks.
If Mitigated
Limited impact if proper network segmentation, least privilege principles, and input validation are implemented, potentially containing the attack to isolated environments.
🎯 Exploit Status
Exploitation requires crafting malicious Schematron files or PDFs that trigger the vulnerable XSL transformation. No public exploit code has been identified at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.24.2
Vendor Advisory: https://github.com/veraPDF/veraPDF-library/security/advisories/GHSA-qxqf-2mfx-x8jw
Restart Required: Yes
Instructions:
1. Stop all services using veraPDF-library. 2. Update to version 1.24.2 using your package manager or by downloading from GitHub. 3. Restart affected services. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable custom Schematron policy checks
allPrevent execution of custom Schematron files that trigger the vulnerable XSL transformation
Configure application to use only built-in validation policies
Remove or restrict access to custom Schematron files
Network isolation
allRestrict network access to veraPDF services
Configure firewall rules to limit inbound connections
Use network segmentation to isolate veraPDF instances
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all Schematron files and PDF inputs
- Run veraPDF-library in a sandboxed environment with minimal privileges and network access
🔍 How to Verify
Check if Vulnerable:
Check if veraPDF-library version is below 1.24.2 and if custom Schematron policy checks are enabledCheck Version:
java -jar verapdf-*.jar --versionVerify Fix Applied:
Verify version is 1.24.2 or higher using the version check command and test that custom Schematron policy checks work without security warnings📡 Detection & Monitoring
Log Indicators:
- Unusual process execution from veraPDF context
- Errors or warnings related to XSL transformations
- Multiple failed policy validation attempts
Network Indicators:
- Unexpected outbound connections from veraPDF hosts
- Unusual network traffic patterns to/from PDF processing services
SIEM Query:
source="veraPDF" AND (event_type="process_execution" OR event_type="xsl_transform")🔗 References
- https://github.com/veraPDF/veraPDF-library/commit/614ffa477a2cf0819e4b0df1ab133610e0da25fb
- https://github.com/veraPDF/veraPDF-library/commit/9386ecbe1a1d1fb9e886d19df28851ed07890d9f
- https://github.com/veraPDF/veraPDF-library/commit/d5314cbdf4e058e0716f80dbdad2dbd8d96e6bfe
- https://github.com/veraPDF/veraPDF-library/issues/1415
- https://github.com/veraPDF/veraPDF-library/security/advisories/GHSA-qxqf-2mfx-x8jw
- https://github.com/veraPDF/veraPDF-library/commit/614ffa477a2cf0819e4b0df1ab133610e0da25fb
- https://github.com/veraPDF/veraPDF-library/commit/9386ecbe1a1d1fb9e886d19df28851ed07890d9f
- https://github.com/veraPDF/veraPDF-library/commit/d5314cbdf4e058e0716f80dbdad2dbd8d96e6bfe
- https://github.com/veraPDF/veraPDF-library/issues/1415
- https://github.com/veraPDF/veraPDF-library/security/advisories/GHSA-qxqf-2mfx-x8jw
