# CVE-2020-11633: Memory corruption in n/a

> A stack-based buffer overflow in the Zscaler Client Connector allows attackers to execute arbitrary code with system privileges via malicious TLS servers.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jul 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-4p36-pgfp-hv82

## What is CVE-2020-11633?

CVE-2020-11633 is a critical memory corruption vulnerability in n/a, published on 15 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Zscaler Client Connector for Windows prior to 2.1.2.74 had a stack based buffer overflow when connecting to misconfigured TLS servers. An adversary would potentially have been able to execute arbitrary code with system privileges.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-11633?

It affects 1 product.


Products: Zscaler Client Connector.

## How do I fix CVE-2020-11633?

No fix has been published for CVE-2020-11633 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-11633 being exploited?

There is no known exploitation of CVE-2020-11633 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [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)
- [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-2020-11633 and fix it if it is affected.

What it is: CVE-2020-11633 is a critical memory corruption vulnerability in n/a, published on 15 Jul 2021. 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-2020-11633 in the wild and no public exploit code.

Affected product: n/a. 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-2020-11633/ (Markdown: https://insights.sbomify.com/CVE-2020-11633/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-11633
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-11633
- OSV: https://osv.dev/vulnerability/CVE-2020-11633

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-11633/
Summaries are generated and may contain mistakes; the official description above is the record.