CyberSecBulletin
CVE-2023-4486NVD status: Modified

Metasys NAE55/SNE/SNC: Allocation of Resources Without Limits or Throttling

Published Updated By the CyberSecBulletin desk

CVE-2023-4486 is a high-severity allocation of resources without limits or throttling vulnerability in Metasys NAE55/SNE/SNC from Johnson Controls, with a CVSS 3.1 base score of 7.5 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 12.0.4, 11.0.6 as the first without the flaw, so updating Metasys NAE55/SNE/SNC to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.83% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Metasys NAE55/SNE/SNC to 12.0.4 or 11.0.6, whichever matches your release line, or a later version.
  2. Update Facility Explorer F4-SNC to 12.0.4 or 11.0.6, whichever matches your release line, or a later version.
  3. Update Nae55 Firmware to 12.0.4 or a later version.
  4. Read the advisory on johnsoncontrols.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
Johnson ControlsMetasys NAE55/SNE/SNC12.0 up to, but not including, 12.0.4; 11.0 up to, but not including, 11.0.612.0.4, 11.0.6
Johnson ControlsFacility Explorer F4-SNC12.0 up to, but not including, 12.0.4; 11.0 up to, but not including, 11.0.612.0.4, 11.0.6
JohnsoncontrolsNae55 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSne22000 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSne11000 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSne10500 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSne110l0 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSnc25150-0 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSnc25150-04 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSnc16120-0 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsSnc16120-04 Firmwarebefore 12.0.412.0.4
JohnsoncontrolsF4-snc Firmwarebefore 11.0.6; 12.0.0 up to, but not including, 12.0.411.0.6, 12.0.4

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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (jci.com)
CVSS 3.17.5HighNVD

Official description

Under certain circumstances, invalid authentication credentials could be sent to the login endpoint of Johnson Controls Metasys NAE55, SNE, and SNC engines prior to versions 11.0.6 and 12.0.4 and Facility Explorer F4-SNC engines prior to versions 11.0.6 and 12.0.4 to cause denial-of-service.

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

The underlying weakness: Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

How developers prevent this class of flaw

  • Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
  • Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)

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

Third-party and government advisories

Recent Allocation of Resources Without Limits or Throttling vulnerabilities

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