Source: security@qnapsecurity.com.tw
An out-of-bounds read vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to obtain secret data. We have already fixed the vulnerability in the following versions: QTS 5.2.7.3256 build 20250913 and later QuTS hero h5.2.7.3256 build 20250913 and later QuTS hero h5.3.1.3250 build 20250912 and later
QNAP NAS devices are vulnerable to an out-of-bounds read vulnerability, allowing attackers with administrator privileges to steal sensitive data. This flaw could lead to data breaches and compromise the confidentiality of stored information. Organizations using affected QNAP devices should immediately update to the patched versions.
Step 1: Administrator Account Compromise: The attacker must first gain administrator-level access to the QNAP device. This could be achieved through various means, such as brute-forcing weak passwords, exploiting other vulnerabilities, or social engineering. Step 2: Triggering the Vulnerability: Once administrator access is obtained, the attacker crafts a malicious request or input designed to trigger the out-of-bounds read. The specific input will depend on the vulnerable component and how it handles data access. Step 3: Out-of-Bounds Read: The crafted input causes the vulnerable code to read data from memory locations outside the intended boundaries. This data may contain sensitive information. Step 4: Data Exfiltration: The attacker extracts the leaked data, which could include credentials, configuration files, or other sensitive information, depending on the memory contents.
The vulnerability stems from an out-of-bounds read within a QNAP operating system component. The root cause likely involves improper bounds checking when accessing a data structure, such as an array or buffer. When an attacker-controlled input is processed, the system attempts to read data from a memory location outside the allocated boundaries. This allows an attacker to read sensitive information stored in adjacent memory locations, potentially including user credentials, encryption keys, or other confidential data. The lack of robust input validation and boundary checks is the core technical flaw.
While no specific APTs or malware are explicitly linked to this CVE, QNAP NAS devices are frequently targeted by ransomware groups and other malicious actors. The vulnerability could be integrated into existing attack chains. CISA KEV status: Not Applicable at this time, but could be added if actively exploited.
Monitor QNAP device logs for suspicious activity, such as unusual file access patterns or unauthorized configuration changes.
Analyze network traffic for unusual requests or data transfers originating from the QNAP device.
Implement file integrity monitoring to detect unauthorized modifications to critical system files.
Review system logs for errors or warnings related to memory access or data processing.
Use a Security Information and Event Management (SIEM) system to correlate events and identify potential exploitation attempts.
Immediately update QNAP devices to the patched versions listed in the advisory (QTS 5.2.7.3256 build 20250913 and later, QuTS hero h5.2.7.3256 build 20250913 and later, QuTS hero h5.3.1.3250 build 20250912 and later).
Enforce strong password policies and multi-factor authentication (MFA) for all administrator accounts.
Regularly back up data stored on QNAP devices to ensure data recovery in case of a breach.
Implement network segmentation to isolate QNAP devices from other critical network resources.
Review and restrict access to the QNAP device's management interface.
Enable automatic security updates to ensure timely patching of future vulnerabilities.