CVE-2023-28803 — An authentication bypass by spoofing of a device with a synthetic IP address is

An authentication bypass by spoofing of a device with a synthetic IP address is possible in Zscaler Client Connector on Windows, allowing a functionality bypass. This issue affects Client Connector: before 3.9.

01What is this vulnerability?

An authentication bypass by spoofing of a device with a synthetic IP address is possible in Zscaler Client Connector on Windows, allowing a functionality bypass. This issue affects Client Connector: before 3.9.

02Affected products

Vendor	Product	Versions
Zscaler	Client Connector	0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-10-23T13:32:17.505Z
• Last modified: 2024-09-11T14:31:41.067Z

09References

• help.zscaler.com — https://help.zscaler.com/client-connector/client-connector-app-release-summary-2…