CVE-2025-67825 Overview
CVE-2025-67825 is a Certificate Validation Bypass vulnerability discovered in Nitro PDF Pro for Windows before version 14.42.0.34. The vulnerability occurs when the application displays signer information from a non-verified PDF field rather than from the verified certificate subject. This inconsistency could allow a malicious document to present misleading signer details to users, potentially undermining the trust model of digital signatures in PDF documents.
Critical Impact
Attackers could craft PDF documents that display inconsistent or misleading signer information, potentially deceiving users into trusting documents that were not properly verified against the certificate authority chain.
Affected Products
- Nitro PDF Pro for Windows versions prior to 14.42.0.34
Discovery Timeline
- 2026-01-08 - CVE CVE-2025-67825 published to NVD
- 2026-01-08 - Last updated in NVD database
Technical Details for CVE-2025-67825
Vulnerability Analysis
This vulnerability represents a flaw in the certificate verification display logic within Nitro PDF Pro. When processing digitally signed PDF documents, the application fails to consistently display signer information derived from the verified certificate identity. Instead, in certain circumstances, the software presents signer details from non-verified PDF fields, which could be manipulated by an attacker.
Digital signature verification in PDF documents relies on a chain of trust established through certificate authorities. When this chain is properly validated, users should see signer information that corresponds to the verified certificate subject. The vulnerability breaks this trust model by potentially displaying unverified metadata to users, creating an opportunity for social engineering attacks through document forgery.
Root Cause
The root cause of this vulnerability lies in the display logic implementation within Nitro PDF Pro. The application's code path for rendering signer information did not consistently prioritize the verified certificate subject data. Instead, it could fall back to non-verified PDF metadata fields in certain edge cases, allowing document creators to inject misleading signer information that would be displayed to end users regardless of the actual certificate verification status.
Attack Vector
An attacker could exploit this vulnerability by crafting a malicious PDF document with manipulated signature metadata fields. When a victim opens this document in a vulnerable version of Nitro PDF Pro, the application would display the attacker-controlled signer information rather than the information from the verified certificate. This could lead users to trust a document based on false signer credentials, potentially enabling:
- Social engineering attacks using forged corporate or government identities
- Distribution of malicious contracts or legal documents with fabricated signatures
- Bypass of document authentication workflows that rely on visual verification
The attack requires user interaction to open the malicious PDF document in the affected application.
Detection Methods for CVE-2025-67825
Indicators of Compromise
- PDF documents with discrepancies between displayed signer information and embedded certificate details
- Documents where metadata signer fields differ significantly from X.509 certificate subject information
- Unusual PDF signature structures with modified or non-standard signer display fields
Detection Strategies
- Audit Nitro PDF Pro installations across the enterprise to identify versions prior to 14.42.0.34
- Implement endpoint monitoring to track PDF document processing for anomalies in signature verification workflows
- Review document signing logs for inconsistencies between reported signer names and certificate authorities
Monitoring Recommendations
- Monitor for installation of outdated Nitro PDF Pro versions on managed endpoints
- Implement file integrity monitoring on critical signed documents
- Enable logging for PDF signature verification events where supported
How to Mitigate CVE-2025-67825
Immediate Actions Required
- Update Nitro PDF Pro for Windows to version 14.42.0.34 or later immediately
- Verify all deployed instances of Nitro PDF Pro across the organization are patched
- Educate users to verify signer certificates through the detailed certificate view rather than relying solely on displayed signer names
- Consider temporarily restricting the opening of externally-sourced signed PDFs until patching is complete
Patch Information
Nitro has addressed this vulnerability in Nitro PDF Pro version 14.42.0.34. The fix updates the display logic to ensure signer information consistently reflects the verified certificate identity. Organizations should prioritize updating to this version or later. For detailed release information, refer to the Gonitro Release Notes.
Workarounds
- Manually verify certificate details by examining the full certificate chain rather than relying on the displayed signer summary
- Use alternative PDF readers with verified signature handling for critical document verification workflows
- Implement organizational policies requiring secondary verification of signed documents through independent tools
- Configure endpoint protection to block or quarantine PDF files from untrusted sources pending review
For additional information about Nitro PDF Pro and security updates, visit the Gonitro Official Website.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
