CVE-2024-53699: QNAP QTS Buffer Overflow Vulnerability

CVE-2024-53699 Overview

CVE-2024-53699 is an out-of-bounds write vulnerability [CWE-787] affecting multiple versions of QNAP QTS and QuTS hero operating systems. The flaw allows remote attackers who already possess administrator credentials to modify or corrupt memory on the target device. QNAP addressed the vulnerability in QTS 5.2.3.3006 build 20250108 and QuTS hero h5.2.3.3006 build 20250108 and later releases. The issue is tracked in QNAP Security Advisory QSA-24-54.

Critical Impact
Authenticated remote attackers with administrator privileges can trigger memory corruption on affected QNAP network-attached storage (NAS) appliances, potentially destabilizing the operating system or altering in-memory data structures.

Affected Products

QNAP QTS 5.2.x builds prior to 5.2.3.3006 build 20250108
QNAP QuTS hero h5.2.x builds prior to h5.2.3.3006 build 20250108
QNAP NAS appliances running the affected operating system builds

Discovery Timeline

2025-03-07 - CVE-2024-53699 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-53699

Vulnerability Analysis

The vulnerability is an out-of-bounds write condition within components of the QTS and QuTS hero operating systems used on QNAP NAS devices. An out-of-bounds write occurs when software writes data past the end, or before the beginning, of an allocated buffer. On QNAP appliances, this class of flaw can corrupt adjacent heap or stack structures, alter application state, or cause the affected service to terminate.

Exploitation requires authenticated administrator access to the appliance. Because the attack vector is network-based, an attacker holding valid admin credentials — or one that has already compromised those credentials through phishing, credential reuse, or a prior vulnerability — can reach the vulnerable code path remotely.

Root Cause

QNAP's advisory attributes the issue to improper bounds checking during memory write operations in the affected operating system components. Insufficient validation of an attacker-influenced length or index value permits a write beyond the intended buffer boundary, producing the out-of-bounds write condition characterized by CWE-787.

Attack Vector

An attacker delivers a crafted request over the network to an authenticated administrative interface on a vulnerable QTS or QuTS hero appliance. The request triggers the vulnerable write operation, corrupting memory in the target process. The prerequisite of administrator privileges and the reported high attack complexity limit practical exploitation, which is reflected in the low CVSS 4.0 base score.

No public proof-of-concept exploit or in-the-wild exploitation has been reported. Consult the QNAP Security Advisory QSA-24-54 for the vendor's technical description.

Detection Methods for CVE-2024-53699

Indicators of Compromise

Unexpected crashes, restarts, or coredumps of QTS or QuTS hero services on affected NAS appliances.
Administrator sessions originating from unusual source addresses or geolocations preceding service instability.
Anomalous or malformed administrative API requests captured in QNAP system logs.

Detection Strategies

Inventory NAS assets and verify running QTS or QuTS hero build numbers against the fixed versions listed in QSA-24-54.
Correlate administrator authentication events with subsequent service faults or unexplained reboots on the appliance.
Monitor network traffic to NAS management interfaces for unusual request patterns from administrative accounts.

Monitoring Recommendations

Forward QNAP system and access logs to a centralized logging or SIEM platform for retention and correlation.
Alert on repeated administrator logins from new source addresses and on service restart events within QTS or QuTS hero.
Track privileged account usage on NAS devices and review any administrative activity outside change windows.

How to Mitigate CVE-2024-53699

Immediate Actions Required

Upgrade affected appliances to QTS 5.2.3.3006 build 20250108 or later, or QuTS hero h5.2.3.3006 build 20250108 or later.
Restrict administrative interfaces to trusted management networks and remove any exposure to the public internet.
Rotate administrator credentials and enforce multi-factor authentication for all privileged accounts on the NAS.
Audit administrator account membership and remove unused or shared privileged accounts.

Patch Information

QNAP has released fixed builds addressing CVE-2024-53699. Administrators should apply QTS 5.2.3.3006 build 20250108 or later, or QuTS hero h5.2.3.3006 build 20250108 or later, following the guidance in QNAP Security Advisory QSA-24-54. Updates can be installed through the QTS Control Panel under Firmware Update or by downloading the corresponding image from the QNAP download center.

Workarounds

Disable remote administrative access from untrusted networks and require VPN connectivity for management.
Limit administrator logins to a small number of dedicated, monitored accounts.
Isolate NAS appliances on a segmented network with strict inbound access control lists.

bash

# Verify installed QTS or QuTS hero version from the appliance shell
getcfg System Version -f /etc/config/uLinux.conf
getcfg System "Build Number" -f /etc/config/uLinux.conf

# Confirm the running build matches or exceeds the fixed release:
# QTS       >= 5.2.3.3006 build 20250108
# QuTS hero >= h5.2.3.3006 build 20250108