CVE-2024-50402 Overview
QNAP disclosed a format string vulnerability affecting multiple versions of the QTS and QuTS hero network-attached storage (NAS) operating systems. The flaw stems from use of an externally controlled format string [CWE-134] in an administrative code path. An authenticated remote attacker with administrator access can leverage the issue to read secret data from process memory or modify memory contents on the device.
Critical Impact
Attackers who already hold administrator credentials can extract sensitive process memory or corrupt in-memory state on affected QNAP NAS appliances, undermining data confidentiality and integrity.
Affected Products
- QNAP QTS 5.1.x and 5.2.x prior to 5.1.9.2954 build 20241120 / 5.2.2.2950 build 20241114
- QNAP QuTS hero h5.1.x and h5.2.x prior to h5.1.9.2954 build 20241120 / h5.2.2.2952 build 20241116
- QNAP NAS appliances running the vulnerable QTS or QuTS hero builds listed above
Discovery Timeline
- 2024-12-06 - CVE-2024-50402 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-50402
Vulnerability Analysis
CVE-2024-50402 is a format string vulnerability [CWE-134] in QNAP's QTS and QuTS hero operating systems. The affected code path accepts attacker-influenced input and passes it directly to a formatting function without a fixed format specifier. As a result, format directives supplied in that input are interpreted by the underlying printf-family function rather than treated as literal data.
Exploitation requires administrator privileges (PR:H) and network reachability to the NAS management interface. Successful abuse allows the attacker to read arbitrary values from the process stack or heap using directives such as %x and %s, or to write to memory using %n. The impact scope is limited to the vulnerable process context.
Root Cause
The root cause is a call into a printf-family routine where a user-controlled string is used as the format argument. QNAP has not published source-level details, but the CWE-134 classification indicates that input from an authenticated administrative feature is concatenated into, or supplied directly as, the format string parameter instead of being passed as an argument to a static format specifier such as "%s".
Attack Vector
The vulnerability is exploitable over the network (AV:N) against the NAS management surface. An attacker must first obtain administrator credentials, then submit crafted input containing format directives to the vulnerable endpoint. The high attack complexity (AC:H) reflects the need to align format directives with the target memory layout to achieve reliable disclosure or memory modification.
Because administrator access is a prerequisite, realistic attack scenarios involve credential theft, phishing of NAS operators, reuse of leaked credentials, or chaining with a prior authentication bypass in the same appliance. No public proof-of-concept exploit or in-the-wild exploitation has been reported for this CVE.
Detection Methods for CVE-2024-50402
Indicators of Compromise
- Administrative HTTP or HTTPS requests to the QNAP management interface containing format specifiers such as %s, %x, %n, %p, or long sequences of %08x in parameter values.
- Unexpected crashes, restarts, or segmentation faults of QTS or QuTS hero management daemons logged in /var/log or the QNAP System Log.
- Administrator logins from unfamiliar IP addresses or geographies immediately preceding anomalous configuration changes.
Detection Strategies
- Inspect web server and reverse-proxy logs on the NAS for administrator-authenticated requests whose parameters contain printf format tokens.
- Correlate QNAP audit logs with endpoint and identity telemetry to flag administrator sessions that deviate from baseline behavior.
- Alert on QTS or QuTS hero versions running below the fixed builds when discovered through asset inventory or vulnerability scanning.
Monitoring Recommendations
- Forward QNAP system, connection, and event logs to a centralized SIEM or data lake for retention and correlation with network telemetry.
- Monitor outbound connections from NAS appliances for unexpected destinations that could indicate post-exploitation data staging.
- Track administrator account usage, including new administrator creation, permission changes, and management interface access outside change windows.
How to Mitigate CVE-2024-50402
Immediate Actions Required
- Upgrade QTS to 5.1.9.2954 build 20241120 or 5.2.2.2950 build 20241114 or later.
- Upgrade QuTS hero to h5.1.9.2954 build 20241120 or h5.2.2.2952 build 20241116 or later.
- Rotate administrator credentials and review recent administrator activity for signs of misuse.
- Restrict management interface exposure so it is not reachable from the public internet.
Patch Information
QNAP has released fixed firmware in the versions listed above. Apply the updates via the QTS or QuTS hero Control Panel under System > Firmware Update, or download them from the QNAP Download Center. See the QNAP Security Advisory QSA-24-49 for the official vendor guidance and complete list of fixed builds.
Workarounds
- Limit administrator access to a small, audited set of accounts protected by strong, unique passwords and two-factor authentication.
- Place the NAS management interface behind a VPN or firewall rule that permits access only from trusted administrative networks.
- Disable remote administration features and myQNAPcloud remote access when not strictly required.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
