CVE-2025-23250: Nvidia Nemo Path Traversal Vulnerability

CVE-2025-23250 Overview

CVE-2025-23250 is a critical path traversal vulnerability affecting the NVIDIA NeMo Framework, a platform widely used for building, training, and fine-tuning AI models. This vulnerability allows an attacker to exploit improper limitation of pathname handling to perform arbitrary file writes to restricted directories on the target system. A successful exploitation of this vulnerability could enable remote code execution and data tampering, posing significant risks to organizations using NeMo for AI/ML workloads.

The vulnerability is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), a well-known weakness category that encompasses path traversal attacks. Given the network-accessible attack vector requiring no privileges or user interaction, this vulnerability presents a severe risk to exposed NeMo deployments.

Critical Impact

This vulnerability enables unauthenticated remote attackers to write arbitrary files to restricted directories, potentially leading to remote code execution and complete system compromise on systems running NVIDIA NeMo Framework.

Affected Products

• NVIDIA NeMo Framework (all versions prior to patched release)
• Systems running on Apple macOS
• Systems running on Linux kernel
• Systems running on Microsoft Windows

Discovery Timeline

• 2025-04-22 - CVE-2025-23250 published to NVD
• 2025-09-24 - Last updated in NVD database

Technical Details for CVE-2025-23250

Vulnerability Analysis

This path traversal vulnerability exists within the NVIDIA NeMo Framework's file handling mechanisms. The framework fails to properly sanitize user-supplied pathname inputs, allowing attackers to escape intended directory boundaries using path traversal sequences such as ../ or absolute path references.

The vulnerability enables attackers to write files to arbitrary locations on the filesystem, bypassing directory restrictions that should confine file operations to designated safe directories. Since NeMo Framework is designed for AI model training and deployment, it handles various file operations for model artifacts, configurations, and data processing—any of which could serve as attack entry points.

The attack requires no authentication or user interaction, making it particularly dangerous for internet-exposed deployments. An attacker can exploit this vulnerability remotely over the network to achieve code execution by writing malicious files to locations where they will be automatically executed, such as startup directories, cron job locations, or web application directories.

Root Cause

The root cause of CVE-2025-23250 lies in insufficient input validation and sanitization of file path parameters within the NeMo Framework. When processing file write operations, the application fails to canonicalize paths and verify that the resulting destination remains within the intended directory boundary.

Specifically, the vulnerability stems from:

• Missing or inadequate validation of path components for traversal sequences
• Failure to resolve symbolic links and relative path references before performing security checks
• Absence of allowlist-based directory restrictions for file write operations

Attack Vector

The attack vector for CVE-2025-23250 is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Identifying an exposed NVIDIA NeMo Framework instance accessible over the network
2. Crafting a malicious request containing path traversal sequences in file path parameters
3. Submitting the request to trigger an arbitrary file write operation
4. Writing malicious content (such as a web shell, cron job, or configuration file) to achieve code execution

The vulnerability can be exploited through any NeMo Framework functionality that processes file paths for write operations. Successful exploitation results in the ability to write files with the privileges of the NeMo process, which may include system-level access depending on deployment configuration.

Detection Methods for CVE-2025-23250

Indicators of Compromise

• Unexpected files appearing in system directories such as /etc/cron.d/, startup folders, or web roots
• Log entries showing file write operations with path traversal sequences (../, ..\\, or absolute paths)
• Suspicious NeMo Framework requests containing encoded traversal patterns (%2e%2e%2f, %252e%252e%252f)
• New or modified executable files in system or application directories with timestamps corresponding to NeMo service activity

Detection Strategies

• Monitor NeMo Framework logs for file operations targeting paths outside expected directories
• Implement web application firewall (WAF) rules to detect and block path traversal patterns in request parameters
• Deploy file integrity monitoring (FIM) on critical system directories to detect unauthorized writes
• Use endpoint detection and response (EDR) solutions to monitor for suspicious file creation patterns

Monitoring Recommendations

• Enable verbose logging for NeMo Framework file operations and review logs regularly for anomalies
• Configure alerts for file write operations targeting sensitive system locations from NeMo processes
• Monitor network traffic to NeMo Framework endpoints for requests containing path traversal indicators
• Implement baseline monitoring for the NeMo application's normal file I/O patterns to detect deviations

How to Mitigate CVE-2025-23250

Immediate Actions Required

• Apply the security patch from NVIDIA immediately to all affected NeMo Framework installations
• Restrict network access to NeMo Framework instances using firewall rules and network segmentation
• Implement input validation at the application or reverse proxy layer to block path traversal attempts
• Review and restrict file system permissions for the NeMo service account to minimize impact of exploitation

Patch Information

NVIDIA has released a security update addressing this vulnerability. Organizations should review the NVIDIA Security Advisory for detailed patch information and apply the update to all affected systems immediately.

The patch implements proper path canonicalization and validation to ensure file operations are restricted to intended directories, preventing path traversal attacks.

Workarounds

• Deploy NeMo Framework behind a reverse proxy with path traversal filtering capabilities
• Run NeMo Framework in a containerized environment with limited filesystem access and read-only mounts where possible
• Implement application-level file path validation if source code modifications are feasible
• Use chroot or similar isolation mechanisms to restrict the NeMo process filesystem visibility

# Example: Restrict network access to NeMo Framework using iptables
# Allow access only from trusted internal networks
iptables -A INPUT -p tcp --dport 8080 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP

# Example: Run NeMo in container with restricted filesystem
# Mount data directories as read-only where possible
docker run --read-only \
  -v /app/data:/data:ro \
  -v /app/output:/output:rw \
  --tmpfs /tmp \
  nvidia/nemo:latest