CVE-2021-28799 QNAP Network Attached Storage (NAS): login or permission bypass
In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.
Confirmed exploited by CISA on · US federal patch deadline Apr 21, 2022
What to do
- Install QNAP's security update for Network Attached Storage (NAS). If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Turn on automatic firmware updates and replace gear the maker no longer supports.
- Change default passwords and switch off remote administration and features you do not use.
- Do not put storage boxes or cameras directly on the internet — use the maker's app or a VPN.
Who is affected
Could reach you. Used in ransomware, which spreads to ordinary people and small businesses.
What's at risk: Taken over in bulk to join botnets, used to watch your traffic, or — for storage boxes — locked by ransomware.
The details
- Official name
- QNAP NAS Improper Authorization Vulnerability
- Product
- QNAP Network Attached Storage (NAS)
- CISA description
- QNAP NAS running HBS 3 contains an improper authorization vulnerability which can allow remote attackers to log in to a device.
- Type of flaw
- Login or permission bypass (CWE-285)
- Confirmed exploited
- Mar 31, 2022 — known to be used in ransomware attacks
- US federal patch deadline
- Apr 21, 2022
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Answering about CVE-2021-28799 ·
Questions about CVE-2021-28799
Is CVE-2021-28799 being exploited?
Yes. CISA added CVE-2021-28799 to its Known Exploited Vulnerabilities catalog on Mar 31, 2022, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2021-28799?
Install QNAP's security update for Network Attached Storage (NAS). If no update exists, follow the vendor's workaround or stop using the product until one ships. Turn on automatic firmware updates and replace gear the maker no longer supports.
Am I affected by CVE-2021-28799?
Only if you use QNAP Network Attached Storage (NAS). Used in ransomware, which spreads to ordinary people and small businesses.