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 a remote attacker with administrator privileges to steal sensitive data. Successful exploitation could lead to data breaches and compromise of confidential information stored on affected devices. Immediate patching is crucial to mitigate this risk.
Step 1: Account Compromise: The attacker must first gain administrator 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 logged in as an administrator, the attacker crafts a malicious request or triggers a specific action within the QNAP operating system. The exact nature of this request is unknown but likely involves manipulating data that is then processed by the vulnerable code. Step 3: Out-of-Bounds Read: The crafted request causes the vulnerable code to read data from memory locations outside the intended buffer. This is the core of the out-of-bounds read vulnerability. Step 4: Data Extraction: The attacker can then extract the data read from the out-of-bounds memory locations. This data could contain sensitive information, depending on the memory layout and the specific code path exploited. Step 5: Data Exfiltration: The attacker exfiltrates the stolen data from the QNAP device.
The vulnerability stems from an out-of-bounds read in the QNAP operating system. The root cause is likely an improper bounds check or lack of input validation when processing data, potentially related to file handling or network communication. This allows an attacker to read memory outside the allocated buffer, exposing sensitive information such as configuration files, user credentials, or other secret data. The specific function or logic flaw is not explicitly stated in the provided information, but the vulnerability type points to a flaw in how the system accesses or processes data, potentially due to incorrect indexing or pointer arithmetic. The vulnerability requires administrator privileges, indicating that the flaw exists in a privileged context.
While no specific APTs or malware are directly linked to this vulnerability in the provided information, any threat actor targeting NAS devices could potentially exploit it. The high value of data stored on NAS devices makes them attractive targets for ransomware groups and state-sponsored actors. CISA KEV status: Not Applicable (as the vulnerability is not yet widely known or exploited).
Monitor QNAP device logs for suspicious activity, such as unusual file access patterns, unexpected network connections, or failed login attempts followed by successful administrator logins.
Analyze network traffic for unusual data transfers from the QNAP device, especially if they occur after a successful administrator login.
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, which could indicate exploitation attempts.
Use intrusion detection systems (IDS) and intrusion prevention systems (IPS) to identify and block malicious traffic targeting the QNAP device.
Immediately update QNAP devices to the patched versions: QTS 5.2.7.3256 build 20250913 and later, QuTS hero h5.2.7.3256 build 20250913 and later, and QuTS hero h5.3.1.3250 build 20250912 and later.
Enforce strong password policies for all administrator accounts, including the use of complex passwords and multi-factor authentication (MFA).
Regularly review and audit administrator accounts to ensure only authorized users have access.
Disable unnecessary services and features on the QNAP device to reduce the attack surface.
Implement network segmentation to isolate the QNAP device from other critical systems.
Regularly back up data stored on the QNAP device to ensure data recovery in case of a successful attack.
Monitor the QNAP device for suspicious activity and promptly investigate any alerts or warnings.