CyberSecBulletin
CVE-2023-51392NVD status: Analyzed

Ember ZNet SDK: Use of a Broken or Risky Cryptographic Algorithm

Published Updated By the CyberSecBulletin desk

CVE-2023-51392 is a critical-severity use of a broken or risky cryptographic algorithm vulnerability in Ember ZNet SDK from Silabs.com, 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 version 7.4.0 as the first without the flaw, so updating Ember ZNet SDK to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% 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 Ember ZNet SDK to 7.4.0 or a later version.
  2. 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
Silabs.comEmber ZNet SDK7.2.0 up to, but not including, 7.4.07.4.0
SilabsEmberznet7.2.0 through 7.2.4Not 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
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 3.16.2MediumCNA (silabs.com)
CVSS 3.19.8CriticalNVD

Official description

Ember ZNet between v7.2.0 and v7.4.0 used software AES-CCM instead of integrated hardware cryptographic accelerators, potentially increasing risk of electromagnetic and differential power analysis sidechannel attacks.

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

The underlying weakness: Use of a Broken or Risky Cryptographic Algorithm

The product uses a broken or risky cryptographic algorithm or protocol.

How developers prevent this class of flaw

  • Ensure that the design allows one cryptographic algorithm to be replaced with another in the next generation or version. Where possible, use wrappers to make the interfaces uniform. This will make it easier to upgrade to stronger algorithms. With hardware, design the product at the Intellectual Property (IP) level so that one cryptographic algorithm can be replaced with another in the next generation of the hardware product.
  • Carefully manage and protect cryptographic keys (see CWE-320). If the keys can be guessed or stolen, then the strength of the cryptography itself is irrelevant.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Industry-standard implementations will save development time and may be more likely to avoid errors that can occur during implementation of cryptographic algorithms. Consider the ESAPI Encryption feature.

More Use of a Broken or Risky Cryptographic Algorithm vulnerabilities (CWE-327)

Timeline

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

References

Other references

Other vulnerabilities in Ember ZNet SDK

All Ember ZNet SDK vulnerabilities

Recent Use of a Broken or Risky Cryptographic Algorithm vulnerabilities

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