CyberSecBulletin
CVE-2023-28656NVD status: Analyzed

NGINX Instance Manager: Authorization Bypass Through User-Controlled Key

Published Updated By the CyberSecBulletin desk

CVE-2023-28656 is a high-severity authorization bypass through user-controlled key vulnerability in NGINX Instance Manager from F5, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.9.0 as the first without the flaw, so updating NGINX Instance Manager to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update NGINX Instance Manager to 2.9.0 or a later version.
  2. Update NGINX API Connectivity Manager to 1.5.0 or a later version.
  3. Update NGINX Security Monitoring to 1.3.0 or a later version.
  4. Read the advisory on my.f5.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
F5NGINX Instance Manager2.0.0 up to, but not including, 2.9.02.9.0
F5NGINX API Connectivity Manager1.0.0 up to, but not including, 1.5.01.5.0
F5NGINX Security Monitoring1.0.0 up to, but not including, 1.3.01.3.0
NetAppCloud BackupNot specified in the recordNot stated
NetAppOntap Select DeployNot specified in the recordNot stated

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
LowA basic user account is enough.
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
NoneAvailability is not affected.

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

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (f5.com)
CVSS 3.18.1HighNVD

Official description

NGINX Management Suite may allow an authenticated attacker to gain access to configuration objects outside of their assigned environment. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

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

The underlying weakness: Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

How developers prevent this class of flaw

  • For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
  • Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
  • Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.

More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in NGINX Instance Manager

All NGINX Instance Manager vulnerabilities

Recent Authorization Bypass Through User-Controlled Key vulnerabilities

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