CyberSecBulletin
CVE-2023-28796NVD status: Modified

Client Connector: Improper Verification of Cryptographic Signature

Published Updated By the CyberSecBulletin desk

CVE-2023-28796 is a high-severity improper verification of cryptographic signature vulnerability in Client Connector from Zscaler, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 1.3.1.6 as the first without the flaw, so updating Client Connector to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% 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 Client Connector to 1.3.1.6 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
ZscalerClient Connectorbefore 1.3.1.61.3.1.6

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
LocalThe attacker needs local access or must trick a user into running something.
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
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.1HighCNA (zscaler.com)
CVSS 3.17.8HighNVD

Official description

Improper Verification of Cryptographic Signature vulnerability in Zscaler Client Connector on Linux allows Code Injection. This issue affects Zscaler Client Connector for Linux: before 1.3.1.6.

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

The underlying weakness: Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)

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 vulnerabilities in Client Connector

All Client Connector vulnerabilities

Recent Improper Verification of Cryptographic Signature vulnerabilities

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