CVE-2026-30276: DeftPDF Document Translator RCE Vulnerability

CVE-2026-30276 Overview

An arbitrary file overwrite vulnerability exists in DeftPDF Document Translator v54.0 that allows attackers to overwrite critical internal files via the file import process. This vulnerability (CWE-73: External Control of File Name or Path) can lead to arbitrary code execution or information exposure when successfully exploited.

Critical Impact

Remote attackers can exploit this vulnerability without authentication to overwrite critical system files, potentially leading to complete system compromise through arbitrary code execution or sensitive information disclosure.

Affected Products

• DeftPDF Document Translator v54.0

Discovery Timeline

• 2026-03-31 - CVE-2026-30276 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2026-30276

Vulnerability Analysis

This vulnerability stems from improper handling of file paths during the document import process in DeftPDF Document Translator. The application fails to properly validate or sanitize user-controlled file paths, allowing attackers to specify arbitrary destination paths when importing files. This external control of file name or path (CWE-73) enables malicious actors to write content to locations outside the intended directory structure.

The network-accessible nature of this vulnerability means it can be exploited remotely without requiring any authentication or user interaction. An attacker can craft a malicious import request that specifies a path traversal sequence or absolute path, causing the application to overwrite critical system files or application configuration files.

Root Cause

The root cause is insufficient input validation in the file import functionality. The application accepts user-supplied file paths without proper sanitization, failing to restrict the destination to a safe directory. This allows path traversal sequences (such as ../) or absolute paths to escape the intended file storage location and write to arbitrary locations on the file system.

Attack Vector

The attack is executed over the network without requiring authentication or user interaction. An attacker exploits the file import process by manipulating the destination path parameter to target critical files. By overwriting application binaries, configuration files, or system files, the attacker can achieve arbitrary code execution when the overwritten file is subsequently executed or loaded by the system. Alternatively, overwriting sensitive files can lead to information exposure or denial of service.

The exploitation mechanism involves crafting a malicious import request that includes path traversal sequences or absolute paths to redirect file writes to critical system locations. Technical details regarding specific exploitation techniques can be found in the GitHub Issue #22 Discussion.

Detection Methods for CVE-2026-30276

Indicators of Compromise

• Unexpected file modifications in system directories or application installation paths
• Log entries showing file import operations with path traversal sequences (../, ..\\)
• Unusual file write operations to sensitive directories like /etc/, /usr/bin/, or application configuration folders
• Modified timestamps on critical system or application files that weren't part of scheduled updates

Detection Strategies

• Implement file integrity monitoring (FIM) on critical system and application files to detect unauthorized modifications
• Monitor application logs for file import requests containing suspicious path patterns including ../, ..\\, or absolute paths
• Deploy network-based intrusion detection rules to identify malicious file import requests targeting the DeftPDF Document Translator
• Use endpoint detection and response (EDR) solutions to monitor for anomalous file write operations

Monitoring Recommendations

• Enable detailed logging for all file import operations in DeftPDF Document Translator
• Configure alerts for any file write operations outside the designated document storage directory
• Implement behavioral analysis to detect unusual patterns in file system access by the application process
• Monitor for unexpected child process creation following file import operations, which may indicate successful code execution

How to Mitigate CVE-2026-30276

Immediate Actions Required

• Restrict network access to DeftPDF Document Translator v54.0 to trusted users and networks only
• Implement application-level firewall rules to filter incoming requests containing path traversal patterns
• Consider disabling the file import functionality until a patch is available if it is not business-critical
• Apply the principle of least privilege to the application's file system permissions, restricting write access to only necessary directories

Patch Information

No official patch information is currently available from the vendor. Organizations should monitor the DeftPDF Security Solutions website for security updates and patch releases. Additional technical discussion regarding this vulnerability is available in the GitHub Issue #22 Discussion.

Workarounds

• Configure web application firewall (WAF) rules to block requests containing path traversal sequences in file import parameters
• Implement network segmentation to isolate systems running DeftPDF Document Translator from critical infrastructure
• Use chroot jails or containerization to restrict the application's file system access to a sandboxed environment
• Deploy additional file system access controls using mandatory access control frameworks (SELinux, AppArmor) to prevent writes outside designated directories

# Example: Restrict file system access using AppArmor
# Create profile at /etc/apparmor.d/deftpdf-translator
# Deny write access outside designated document directory
# /path/to/deftpdf-documents/ rw,
# deny /etc/** w,
# deny /usr/** w,
# deny /var/** w,