# CVE-2023-28804: Linux ZCC allows unsigned updates, allowing elevated Code Execution

> Attackers can replace binaries due to missing signature verification, enabling elevated code execution on Linux systems.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Oct 2023
- **Updated:** 17 Oct 2024
- **Also known as:** GHSA-h7x8-97pc-7qrv

## What is CVE-2023-28804?

CVE-2023-28804 is a high-severity vulnerability in Zscaler Client Connector, published on 23 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Improper Verification of Cryptographic Signature vulnerability in Zscaler Client Connector on Linux allows replacing binaries.This issue affects Linux Client Connector: before 1.4.0.105

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

## Which versions are affected by CVE-2023-28804?

It affects 1 product.


Products: Zscaler Client Connector.

## How do I fix CVE-2023-28804?

No fix has been published for CVE-2023-28804 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-28804 being exploited?

There is no known exploitation of CVE-2023-28804 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-2023-28799](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)
- [CVE-2024-23456](https://insights.sbomify.com/CVE-2024-23456/): Signature validation issue leads to Anti-Tampering bypass (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-28804 and fix it if it is affected.

What it is: CVE-2023-28804 is a high-severity vulnerability in Zscaler Client Connector, published on 23 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-28804 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-2023-28804/ (Markdown: https://insights.sbomify.com/CVE-2023-28804/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-28804
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-28804
- OSV: https://osv.dev/vulnerability/CVE-2023-28804

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-28804/
Summaries are generated and may contain mistakes; the official description above is the record.