CVE-2020-2506
QNAP Helpdesk Improper Access Control Vulnerability
Description
CVE-2020-2506 is a high-severity improper access control vulnerability in QNAP Helpdesk that allows remote attackers to gain unauthorized access to affected QNAP NAS devices. The vulnerability stems from insufficient access control enforcement in the Helpdesk application, enabling attackers to bypass authentication mechanisms and access restricted functionality. CISA has added CVE-2020-2506 to the Known Exploited Vulnerabilities catalog due to confirmed active exploitation. With an EPSS score of 18.0% (87.3rd percentile), this vulnerability represents a significant threat to organizations running vulnerable QNAP NAS devices with the Helpdesk application enabled.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:LOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| qnap | helpdesk | < 3.0.3 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://www.qnap.com/zh-tw/security-advisory/qsa-20-08(Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-2506(US Government Resource)
Weakness Type
CWE-284: Improper Access Control
CWE-284 describes a weakness where software does not properly restrict access to resources or functionality, allowing unauthorized actors to perform actions that should be limited to privileged users. In CVE-2020-2506, the QNAP Helpdesk application fails to enforce proper access controls, enabling remote attackers to bypass authentication and access restricted administrative functions on the NAS device without proper authorization.
Learn more: CWE-284 — Improper Access Control
Impact Analysis
CVE-2020-2506 enables remote attackers to bypass access controls in QNAP Helpdesk, potentially gaining unauthorized access to the NAS device's administrative functions. QNAP NAS devices are widely used for file storage, backup, and data sharing in both business and home environments, making them attractive targets for data theft and ransomware deployment. Successful exploitation can allow attackers to access all stored data, modify device configurations, create unauthorized user accounts, and potentially escalate privileges to gain full control of the device. When combined with CVE-2020-2507 (a related command injection vulnerability), attackers can chain the vulnerabilities to achieve full remote code execution. The 87.3rd percentile EPSS score indicates significant exploitation activity in the wild.
Exploit Maturity
CVE-2020-2506 is actively exploited in the wild, as confirmed by its inclusion in the CISA Known Exploited Vulnerabilities catalog. The vulnerability is often exploited in conjunction with CVE-2020-2507 to achieve a complete attack chain from unauthorized access to remote code execution on QNAP NAS devices. QNAP NAS devices have been consistently targeted by ransomware groups, and the EPSS score of 18.0% (87.3rd percentile) reflects significant ongoing exploitation activity. The widespread deployment of QNAP NAS devices in internet-facing configurations increases the available attack surface.
Remediation
- Update the QNAP Helpdesk application to version 3.0.3 or later immediately, as this version addresses the improper access control vulnerability. Apply updates via the QNAP App Center on your NAS device.
- If the Helpdesk application is not required, disable or uninstall it entirely from the QNAP NAS device to eliminate the attack surface.
- Ensure the QNAP NAS device is not directly accessible from the internet; place it behind a firewall and disable UPnP port forwarding to prevent unintended internet exposure.
- Change all administrative and user credentials on the NAS device, and enable two-factor authentication for all accounts to mitigate the risk of unauthorized access.
- Review NAS access logs for signs of unauthorized access or suspicious activity, and check for any unauthorized user accounts, modified configurations, or unexpected file changes that may indicate prior exploitation.
Technical Details
CVE-2020-2506 is an improper access control vulnerability (CWE-284) in the QNAP Helpdesk application installed on QNAP NAS devices. The vulnerability exists because the Helpdesk application does not properly enforce authentication and authorization checks on certain API endpoints or administrative functions, allowing remote attackers to bypass access controls and interact with restricted functionality. The vulnerability affects Helpdesk versions prior to 3.0.3. QNAP NAS devices commonly run multiple applications including Helpdesk as part of their management suite, and the improper access control in this component can serve as an entry point for further attacks against the NAS operating system. When chained with CVE-2020-2507, which provides command injection capability, the combined vulnerabilities enable complete remote compromise of the device.
Frequently Asked Questions
Is CVE-2020-2506 being actively exploited?
Yes, CVE-2020-2506 is actively exploited in the wild and is listed in the CISA Known Exploited Vulnerabilities catalog. The vulnerability is frequently exploited together with CVE-2020-2507 to achieve full remote code execution on QNAP NAS devices. The EPSS score of 18.0% (87.3rd percentile) confirms significant exploitation activity.
What products are affected by CVE-2020-2506?
CVE-2020-2506 affects QNAP NAS devices running the Helpdesk application in versions prior to 3.0.3. Any QNAP NAS with the vulnerable Helpdesk application installed and accessible over the network is at risk.
How do I fix CVE-2020-2506?
Update the QNAP Helpdesk application to version 3.0.3 or later via the QNAP App Center. If the Helpdesk application is not needed, disable or uninstall it entirely. Additionally, ensure the NAS device is not directly accessible from the internet and enable two-factor authentication for all accounts.
How severe is CVE-2020-2506?
CVE-2020-2506 is rated HIGH severity as it enables unauthorized access to restricted functions on QNAP NAS devices. When combined with CVE-2020-2507, it allows full remote code execution. The EPSS score of 18.0% (87.3rd percentile) indicates significant exploitation, and QNAP NAS devices have been repeatedly targeted by ransomware operators.
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