CVE-2023-28803

MEDIUMNVD 5.95.9—

5.9

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.

CVSS v3: 5.9
EG Score: 5.9(medium)
EPSS: 0.6%
KEV: Not listed

Published

October 23, 2023

Last Modified

November 21, 2024

References (2)

cve@zscalerhttps://help.zscaler.com/client-connector/client-connector-app-release-summary-2023
af854a3a-2127-422b-91ae-364da2661108https://help.zscaler.com/client-connector/client-connector-app-release-summary-2023

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-290Authentication Bypass by Spoofing

Data Freshness Timeline

(refreshed 11× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:12 UTCepss_batch
2026-06-02 20:12 UTCepss_batch
2026-06-02 20:12 UTCepss_batch
2026-06-01 13:51 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:43 UTCepss_batch
2026-05-26 13:43 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-24 15:22 UTCEG score recompute
2026-05-24 15:22 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2023-28803?

CVE-2023-28803 is a medium vulnerability published on October 23, 2023. 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.

When was CVE-2023-28803 disclosed?

CVE-2023-28803 was first published in the National Vulnerability Database on October 23, 2023, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2023-28803 actively exploited?

CVE-2023-28803 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2023-28803?

CVE-2023-28803 has a CVSS v3 base score of 5.9 (NVD).

How do I remediate CVE-2023-28803?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-28803, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-28803

Explore →

Is Your Infrastructure Affected by CVE-2023-28803?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2023-28803

📅 Published

🔄 Last Modified

🔗 References (2)