# CVE-2020-3542: Cisco Webex Training Unauthorized Meeting Join Vulnerability

> Authenticated attackers can bypass meeting password protection to join private sessions via API manipulation, requiring Cisco Webex Training users to apply vendor patches.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Sep 2020
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-f5m9-r5hc-4gww

## What is CVE-2020-3542?

CVE-2020-3542 is a medium-severity authentication bypass vulnerability in Cisco Webex Meetings, published on 4 Sep 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in Cisco Webex Training could allow an authenticated, remote attacker to join a password-protected meeting without providing the meeting password. The vulnerability is due to improper validation of input to API requests that are a part of meeting join flow. An attacker could exploit this vulnerability by sending an API request to the application, which would return a URL that includes a meeting join page that is prepopulated with the meeting username and password. A successful exploit could allow the attacker to join the password-protected meeting. The attacker would be visible in the attendee list of the meeting.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-3542?

It affects 1 product.


Products: Cisco Webex Training.

## How do I fix CVE-2020-3542?

No fix has been published for CVE-2020-3542 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3542 being exploited?

There is no known exploitation of CVE-2020-3542 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3542 and fix it if it is affected.

What it is: CVE-2020-3542 is a medium-severity authentication bypass vulnerability in Cisco Webex Meetings, published on 4 Sep 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-3542 in the wild and no public exploit code.

Affected product: Cisco Webex Meetings. 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-2020-3542/ (Markdown: https://insights.sbomify.com/CVE-2020-3542/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3542
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3542
- OSV: https://osv.dev/vulnerability/CVE-2020-3542

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3542/
Summaries are generated and may contain mistakes; the official description above is the record.