CVE-2026-22625: HIKSEMI NAS Information Disclosure Flaw

CVE-2026-22625 Overview

CVE-2026-22625 is a Path Traversal vulnerability affecting certain HIKSEMI NAS products. The vulnerability stems from improper handling of filenames, which may allow an attacker with physical access to the device to expose sensitive system files. This type of vulnerability typically occurs when user-controlled input is used to construct file paths without adequate validation or sanitization, enabling attackers to access files outside the intended directory structure.

Critical Impact

Physical access to affected HIKSEMI NAS devices could result in unauthorized disclosure of sensitive system files, potentially exposing configuration data, credentials, or other confidential information stored on the device.

Affected Products

• HIKSEMI NAS Products (specific models not disclosed)

Discovery Timeline

• 2026-01-30 - CVE-2026-22625 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-22625

Vulnerability Analysis

This vulnerability represents an information disclosure issue within HIKSEMI NAS products caused by improper filename handling. The attack requires physical access to the device, which limits the attack surface but still poses a significant risk in environments where physical device security cannot be guaranteed.

The vulnerability allows attackers to bypass normal file access restrictions and retrieve sensitive system files. In NAS environments, such files might include system configuration files, user credentials, encryption keys, or backup data. The impact is limited to confidentiality—there is no indication that this vulnerability allows for file modification or system availability disruption.

Root Cause

The root cause of CVE-2026-22625 is improper input validation when processing filenames. The affected HIKSEMI NAS firmware fails to properly sanitize or validate filename inputs, allowing specially crafted path sequences to traverse outside the intended directory boundaries. This is a classic path traversal weakness where insufficient filtering of path separators or parent directory references (such as ../) enables unauthorized file access.

Attack Vector

The attack vector requires physical access to the affected NAS device. An attacker with direct access could exploit the improper filename handling mechanism to craft requests that traverse the filesystem hierarchy. By manipulating filename parameters with directory traversal sequences, the attacker can navigate outside restricted directories and access sensitive system files.

Typical exploitation would involve:

1. Gaining physical access to the HIKSEMI NAS device
2. Interacting with the device interface that handles file operations
3. Submitting filenames containing path traversal sequences (e.g., ../../etc/passwd)
4. Retrieving sensitive system files that should not be accessible

Since no verified code examples are available for this vulnerability, please refer to the Hiksemi Security Advisory for additional technical details and remediation guidance.

Detection Methods for CVE-2026-22625

Indicators of Compromise

• Unexpected file access attempts targeting system directories outside normal NAS storage paths
• Log entries showing requests with path traversal patterns such as ../ or encoded variants
• Access to sensitive system files like /etc/passwd, /etc/shadow, or configuration files from unauthorized sources

Detection Strategies

• Monitor NAS device logs for file access requests containing directory traversal sequences
• Implement file integrity monitoring on critical system files to detect unauthorized access
• Review physical access logs to correlate device access with suspicious file retrieval activities

Monitoring Recommendations

• Enable comprehensive logging on HIKSEMI NAS devices and forward logs to a centralized SIEM
• Set up alerts for access attempts to sensitive system directories
• Regularly audit physical access controls to NAS device locations
• Deploy SentinelOne Singularity platform to monitor for anomalous file access patterns on network-attached storage infrastructure

How to Mitigate CVE-2026-22625

Immediate Actions Required

• Review and restrict physical access to affected HIKSEMI NAS devices
• Check the Hiksemi Security Advisory for available firmware updates
• Audit access logs for any signs of prior exploitation attempts
• Implement network segmentation to isolate NAS devices from untrusted network segments

Patch Information

HIKSEMI has published a security advisory addressing this vulnerability. Administrators should consult the Hiksemi Security Advisory page to identify affected product versions and obtain the appropriate firmware updates. Apply all available security patches as soon as they become available.

Workarounds

• Restrict physical access to HIKSEMI NAS devices to authorized personnel only
• Place NAS devices in secured locations with access controls (locked server rooms, security badges)
• Implement monitoring solutions to detect and alert on unauthorized physical access attempts
• Consider disabling unnecessary services or interfaces that may expose file handling functionality

# Example: Restrict physical console access and enable logging
# Consult HIKSEMI documentation for device-specific commands

# Verify firmware version
cat /etc/version

# Review access logs for suspicious activity
grep -E "\.\./|\.\.%2F" /var/log/access.log

# Enable enhanced logging if available
# (Refer to HIKSEMI administration guide for specific configuration)