Attacker Value
Very High
(1 user assessed)
Exploitability
Very High
(1 user assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
1

CVE-2021-28799

Disclosure Date: April 22, 2021
Exploited in the Wild
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

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 .

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2
Ratings
  • Attacker Value
    Very High
  • Exploitability
    Very High
Technical Analysis

Both Palo Alto Networks and Netlab360 (ostensibly, since Netlab360 doesn’t specify any CVEs) have write-ups on widespread attacks leveraging this bug starting in April and going through at least August, including ransomware campaigns. QNAP’s advisory is pretty sparse, but from the news coverage it sounds like this was a hard-coded creds bug that allowed an attacker to log into a vulnerable device (which evidently QLocker and ech0raix ransomware operators did). Yikes—hopefully folks have patched by now.

CVSS V3 Severity and Metrics
Base Score:
9.8 Critical
Impact Score:
5.9
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • QNAP Systems Inc.

Products

  • HBS 3,
  • HBS 2,
  • HBS 1.3

Exploited in the Wild

Reported by:

Additional Info

Technical Analysis