# CVE-2023-28806: Signature validation error in DLL allows disabling anti-tampering protection

> An authenticated user can bypass anti-tampering protections in Zscaler Client Connector for Windows due to improper signature validation.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2024
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-hrw8-hpf8-7q72

## What is CVE-2023-28806?

CVE-2023-28806 is a medium-severity vulnerability in Zscaler Client Connector, published on 6 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Improper Validation of signature in Zscaler Client Connector on Windows allows an authenticated user to disable anti-tampering. This issue affects Client Connector on Windows <4.2.0.190.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2023-28806?

It affects 1 product.


Products: Zscaler Client Connector.

## How do I fix CVE-2023-28806?

No fix has been published for CVE-2023-28806 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-28806 being exploited?

There is no known exploitation of CVE-2023-28806 in the wild and no public exploit code.

## Other vulnerabilities in Zscaler Client Connector

- [CVE-2020-11633](https://insights.sbomify.com/CVE-2020-11633/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-23463](https://insights.sbomify.com/CVE-2024-23463/): Anti-Tampering bypass via Repair App functionality (high 8.8)
- [CVE-2023-28804](https://insights.sbomify.com/CVE-2023-28804/): Linux ZCC allows unsigned updates, allowing elevated Code Execution (high 8.2)
- [CVE-2023-28799](https://insights.sbomify.com/CVE-2023-28799/): Open redirect in Client Connector (high 8.2)
- [CVE-2023-28800](https://insights.sbomify.com/CVE-2023-28800/): Output encoding missing in redrurl parameter (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-28806 and fix it if it is affected.

What it is: CVE-2023-28806 is a medium-severity vulnerability in Zscaler Client Connector, published on 6 Aug 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-28806 in the wild and no public exploit code.

Affected product: Zscaler Client Connector. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-28806/ (Markdown: https://insights.sbomify.com/CVE-2023-28806/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-28806
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-28806
- OSV: https://osv.dev/vulnerability/CVE-2023-28806

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-28806/
Summaries are generated and may contain mistakes; the official description above is the record.