CVE-2025-49153: Unauthenticated RCE Vulnerability

CVE-2025-49153 Overview

CVE-2025-49153 is a critical path traversal vulnerability (CWE-22) that allows unauthenticated attackers to overwrite files and execute arbitrary code on affected systems. This vulnerability poses a severe risk to industrial control systems (ICS) environments, as it requires no authentication and can be exploited remotely over the network.

Critical Impact

Unauthenticated remote attackers can leverage this path traversal flaw to overwrite critical system files and achieve arbitrary code execution, potentially compromising entire industrial control systems.

Affected Products

• Industrial Control Systems (ICS) products as identified in CISA Advisory ICSA-25-175-07
• Refer to the CISA ICS Advisory for the complete list of affected products and versions

Discovery Timeline

• 2025-06-25 - CVE-2025-49153 published to NVD
• 2025-07-17 - Last updated in NVD database

Technical Details for CVE-2025-49153

Vulnerability Analysis

This vulnerability stems from improper path validation (CWE-22: Path Traversal), which allows attackers to manipulate file paths to access directories outside the intended scope. Because the vulnerability requires no authentication and can be exploited over the network, attackers can remotely target vulnerable systems without any prior access or credentials.

The combination of unauthenticated access and the ability to overwrite files creates a dangerous attack surface. Once an attacker can write arbitrary content to arbitrary locations on the file system, they can achieve code execution by overwriting configuration files, executables, or other critical system components.

Root Cause

The root cause is improper neutralization of special characters in file path inputs. The affected systems fail to properly sanitize user-supplied input that specifies file paths, allowing directory traversal sequences such as ../ to escape the intended directory structure. This improper input validation enables attackers to target files anywhere on the accessible file system.

Attack Vector

The attack is network-based and requires no authentication, making it particularly dangerous for internet-exposed or inadequately segmented ICS environments. An attacker can craft malicious requests containing path traversal sequences to write arbitrary content to sensitive locations on the target system.

The typical attack flow involves:

1. Identifying a vulnerable endpoint that accepts file path input
2. Crafting a request with directory traversal sequences (e.g., ../../) to escape the intended directory
3. Specifying a target file location and malicious content to write
4. Achieving code execution through overwriting executables, configuration files, or placing web shells in accessible locations

For detailed technical information about exploitation vectors, refer to the CISA ICS Advisory ICSA-25-175-07.

Detection Methods for CVE-2025-49153

Indicators of Compromise

• Unexpected file modifications in system directories or application paths
• Presence of path traversal sequences (../, ..%2f, %2e%2e/) in web server or application logs
• Newly created executable files or scripts in sensitive directories
• Unauthorized configuration file changes on ICS systems

Detection Strategies

• Monitor network traffic for HTTP requests containing path traversal patterns targeting vulnerable endpoints
• Implement file integrity monitoring (FIM) on critical system files and directories
• Deploy intrusion detection systems (IDS) with signatures for path traversal attack patterns
• Review application and web server logs for suspicious file access patterns

Monitoring Recommendations

• Enable verbose logging on all affected ICS systems and associated web services
• Configure alerts for file system changes in critical directories
• Monitor for unusual outbound network connections from ICS systems that may indicate post-exploitation activity
• Implement network segmentation monitoring to detect lateral movement attempts

How to Mitigate CVE-2025-49153

Immediate Actions Required

• Consult the CISA ICS Advisory ICSA-25-175-07 for vendor-specific patches and guidance
• Restrict network access to affected systems to trusted networks only
• Implement network segmentation to isolate ICS environments from corporate networks and the internet
• Enable additional logging and monitoring on potentially affected systems

Patch Information

Refer to the CISA ICS Advisory ICSA-25-175-07 for specific patch information from the affected product vendors. Organizations should prioritize applying vendor-supplied patches as they become available, given the critical severity and unauthenticated nature of this vulnerability.

Workarounds

• Deploy web application firewalls (WAF) with rules to block path traversal patterns
• Implement strict input validation at network perimeter devices to filter malicious requests
• Use network access control lists (ACLs) to limit access to affected systems to authorized IP addresses only
• Consider disabling vulnerable functionality if patches are not immediately available

# Example firewall rule to restrict access to ICS systems
# Adjust IP ranges according to your environment
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP