Exploited vulnerability · CISA KEV

Is CVE-2021-28799 exploited? Yes: in CISA KEV since 31 Mar 2022

Gociux · QNAP Network Attached Storage (NAS) · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-28799, QNAP NAS Improper Authorization Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 31 Mar 2022, 322 days after it was published. It is known to be used in ransomware campaigns. It affects QNAP Network Attached Storage (NAS). If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 31 Mar 2022

ransomwareKnownused in campaigns

EPSStop 1%among the most likely CVEs to be exploited

severity10CVSS 3.1 · critical

US federal due21 Apr 2022BOD 22-01 deadline

What it is

QNAP NAS running HBS 3 contains an improper authorization vulnerability which can allow remote attackers to log in to a device.

Vendor	QNAP (11 exploited CVEs in KEV)
Product	Network Attached Storage (NAS)
Vulnerability	QNAP NAS Improper Authorization Vulnerability
Weakness	CWE-285
Published	13 May 2021
Added to KEV	31 Mar 2022
Reported by (CNA)	qnap

What to do

Check whether you run it. Look for Network Attached Storage (NAS) in your asset inventory, including appliances and cloud images. Stack check lists every exploited QNAP CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 13 May 2021.
Get told next time. Email alerts when CISA adds a CVE for QNAP.

Other exploited CVEs in Network Attached Storage (NAS)

CVE-2018-19953: QNAP NAS File Station Cross-Site Scripting Vulnerability (24 May 2022)
CVE-2018-19949: QNAP NAS File Station Command Injection Vulnerability (24 May 2022)
CVE-2018-19943: QNAP NAS File Station Cross-Site Scripting Vulnerability (24 May 2022)

References

nvd.nist.gov/vuln/detail/CVE-2021-28799

Questions

Is CVE-2021-28799 being exploited?

Yes. CISA added CVE-2021-28799 to the Known Exploited Vulnerabilities catalog on 31 Mar 2022, which means there is reliable evidence of exploitation in the wild.

Is CVE-2021-28799 used in ransomware attacks?

Yes, CISA lists it as known to be used in ransomware campaigns.

How do I fix CVE-2021-28799?

Apply updates per vendor instructions. Check QNAP's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected Network Attached Storage (NAS) and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in March 2022 · QNAP scorecard · act-now radar.

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