# CVE-2020-3535: Cisco Webex Teams Client for Windows DLL Hijacking Vulnerability

> Local attackers can execute arbitrary code with another user's privileges by placing a malicious DLL in a specific directory.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Oct 2020
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-v4rq-rq59-hgx8

## What is CVE-2020-3535?

CVE-2020-3535 is a high-severity code injection vulnerability in Cisco Webex Teams, published on 8 Oct 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the loading mechanism of specific DLLs in the Cisco Webex Teams client for Windows could allow an authenticated, local attacker to load a malicious library. To exploit this vulnerability, the attacker needs valid credentials on the Windows system. The vulnerability is due to incorrect handling of directory paths at run time. An attacker could exploit this vulnerability by placing a malicious DLL file in a specific location on the targeted system. This file will execute when the vulnerable application launches. A successful exploit could allow the attacker to execute arbitrary code on the targeted system with the privileges of another user’s account.

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2020-3535?

It affects 1 product.


Products: Cisco Webex Teams.

## How do I fix CVE-2020-3535?

No fix has been published for CVE-2020-3535 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3535 being exploited?

There is no known exploitation of CVE-2020-3535 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Webex Teams

- [CVE-2025-20236](https://insights.sbomify.com/CVE-2025-20236/): Cisco Webex App Client-Side Remote Code Execution Vulnerability (high 8.8)
- [CVE-2018-0387](https://insights.sbomify.com/CVE-2018-0387/): Code injection in Cisco Webex Teams unknown (high 8.8)
- [CVE-2018-0436](https://insights.sbomify.com/CVE-2018-0436/): Cisco Webex Teams Information Disclosure and Modification Vulnerability (high 8.7)
- [CVE-2019-1636](https://insights.sbomify.com/CVE-2019-1636/): Cisco Webex Teams URI Handler Insecure Library Loading Vulnerability (high 7.8)
- [CVE-2019-1939](https://insights.sbomify.com/CVE-2019-1939/): Cisco Webex Teams Logging Feature Command Execution Vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3535 and fix it if it is affected.

What it is: CVE-2020-3535 is a high-severity code injection vulnerability in Cisco Webex Teams, published on 8 Oct 2020. 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-2020-3535 in the wild and no public exploit code.

Affected product: Cisco Webex Teams. 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-2020-3535/ (Markdown: https://insights.sbomify.com/CVE-2020-3535/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3535
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3535
- OSV: https://osv.dev/vulnerability/CVE-2020-3535

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3535/
Summaries are generated and may contain mistakes; the official description above is the record.