Background exploitation KEV catalog Ransomware No authentication

CVE-2021-28799

QNAP NAS Improper Authorization Vulnerability

CheckOps priority index

9.3/10 Patch within 24 h

Severity10.0

Probability7.8

Exploitation5/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 78.3% higher than 99.6% of CVEs

CVSS 3.1 10.0 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:

Exploited for 1,678 days 31 Mar 2022

CISA due date 21 Apr 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 5 / 5

KEV catalog (CISA)31 Mar 2022
Exploited in EUVD (ENISA)31 Mar 2022
Used by ransomwareyes
EPSS above 10 %78.3%
No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If exploited, the vulnerability allows remote attackers to log in to a device. This issue affects: QNAP Systems Inc. HBS 3 versions prior to v16.0.0415 on QTS 4.5.2; versions prior to v3.0.210412 on QTS 4.3.6; versions prior to v3.0.210411 on QTS 4.3.4; versions prior to v3.0.210411 on QTS 4.3.3; versions prior to v16.0.0419 on QuTS hero h4.5.1; versions prior to v16.0.0419 on QuTScloud c4.5.1~c4.5.4. This issue does not affect: QNAP Systems Inc. HBS 2 . QNAP Systems Inc. HBS 1.3 .

Affected products

HBS 3Network Attached Storage (NAS)

Affected versions

unspecified <v3.0.210412
unspecified <v16.0.0419
unspecified <v16.0.0415
unspecified <v3.0.210411

Weaknesses (CWE)

CWE-285

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

13 May 2021
Published
31 Mar 2022
Exploitation reported (ENISA)
31 Mar 2022
Added to the KEV catalog
21 Apr 2022
CISA remediation due date
26 Sept 2026
EPSS peak: 78.3%

References

Other exploited vulnerabilities from the same vendor

CVE-2023-47565QNAP VioStor NVR OS Command Injection Vulnerability
7.2 · Background exploitation
CVE-2022-27593QNAP Photo Station Externally Controlled Reference Vulnerability
9.6 · Background exploitation
CVE-2019-7195QNAP Photo Station Path Traversal Vulnerability
9.6 · Background exploitation
CVE-2019-7194QNAP Photo Station Path Traversal Vulnerability
9.4 · Background exploitation
CVE-2019-7193QNAP QTS Improper Input Validation Vulnerability
7.4 · Background exploitation
CVE-2019-7192QNAP Photo Station Improper Access Control Vulnerability
9.6 · Background exploitation