CVE-2023-28803
Traffic being bypassed by ZCC by configuring synthetic IP range as local network
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Traffic being bypassed by ZCC by configuring synthetic IP range as local network
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.
- Record
CVE-2023-28803- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
EUVDEUVD-2023-32438
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.
- Record
EUVD-2023-32438- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-mwvw-6ggj-fhv5
An authentication bypass by spoofing of a device with a synthetic IP address is possible in...
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.
- Record
GHSA-mwvw-6ggj-fhv5- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2023-28803- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-290
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-28803 is a medium vulnerability (CVSS 5.9) in Zscaler Client Connector, published October 23, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. No source names a fixed version.