CyberSecBulletin
CVE-2023-39303NVD status: Modified

QTS: Improper Authentication

Published Updated By the CyberSecBulletin desk

CVE-2023-39303 is a critical-severity improper authentication vulnerability in QTS from QNAP, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 5.1.3.2578 build 20231110, 5.1.3.2578_build 20231110 as the first without the flaw, so updating QTS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.47% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update QTS to 5.1.3.2578 build 20231110 or 5.1.3.2578_build 20231110, whichever matches your release line, or a later version.
  2. Update QuTS hero to h5.1.3.2578 build 20231110 or 5.1.3.2578_build 20231110, whichever matches your release line, or a later version.
  3. Update QuTScloud to c5.1.5.2651 or 5.1.5.2651, whichever matches your release line, or a later version.
  4. Read the advisory on qnap.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
QNAPQTS5.1.x up to, but not including, 5.1.3.2578 build 20231110; 5.1.0 up to, but not including, 5.1.3.2578_build 202311105.1.3.2578 build 20231110, 5.1.3.2578_build 20231110
QNAPQuTS heroh5.1.x up to, but not including, h5.1.3.2578 build 20231110; 5.1.0 up to, but not including, 5.1.3.2578_build 20231110h5.1.3.2578 build 20231110, 5.1.3.2578_build 20231110
QNAPQuTScloudc5.x.x up to, but not including, c5.1.5.2651; 5.0.0 up to, but not including, 5.1.5.2651c5.1.5.2651, 5.1.5.2651

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.15.3MediumCNA (qnapsecurity.com.tw)
CVSS 3.19.8CriticalNVD

Official description

An improper authentication vulnerability has been reported to affect several QNAP operating system versions. If exploited, the vulnerability could allow users to compromise the security of the system via a network. We have already fixed the vulnerability in the following versions: QTS 5.1.3.2578 build 20231110 and later QuTS hero h5.1.3.2578 build 20231110 and later QuTScloud c5.1.5.2651 and later

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in QTS

All QTS vulnerabilities

Recent Improper Authentication vulnerabilities

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