# CVE-2020-3126: Cisco Webex Meetings Multimedia Viewer Vulnerability

> Authenticated attackers can bypass security warnings in Webex Meetings Multimedia Viewer, allowing malicious files to render in a victim's browser without user consent.

- **Severity:** Low 3.0 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Apr 2020
- **Updated:** 15 Nov 2024
- **Also known as:** GHSA-whw2-mwc3-hmmg

## What is CVE-2020-3126?

CVE-2020-3126 is a low-severity vulnerability in Cisco Webex Meetings Server, published on 13 Apr 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

vulnerability within the Multimedia Viewer feature of Cisco Webex Meetings could allow an authenticated, remote attacker to bypass security protections. The vulnerability is due to missing security warning dialog boxes when a room host views shared multimedia files. An authenticated, remote attacker could exploit this vulnerability by using the host role to share files within the Multimedia sharing feature and convincing a former room host to view that file. A warning dialog normally appears cautioning users before the file is displayed; however, the former host would not see that warning dialog, and any shared multimedia would be rendered within the user's browser. The attacker could leverage this behavior to conduct additional attacks by including malicious files within a targeted room host's browser window.

Weakness: CWE-20 (Improper Input Validation), CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2020-3126?

It affects 1 product.


Products: Cisco Webex Meetings Server.

## How do I fix CVE-2020-3126?

No fix has been published for CVE-2020-3126 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3126 being exploited?

There is no known exploitation of CVE-2020-3126 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Webex Meetings Server

- [CVE-2017-12367](https://insights.sbomify.com/CVE-2017-12367/): Memory corruption in Cisco WebEx Recording Format and Advanced Recording Format Players (critical 9.6)
- [CVE-2015-0589](https://insights.sbomify.com/CVE-2015-0589/): Command injection in n/a (critical 9.0)
- [CVE-2017-3794](https://insights.sbomify.com/CVE-2017-3794/): Cross-site request forgery in Cisco WebEx Meetings Server 2.6 (high 8.8)
- [CVE-2016-1448](https://insights.sbomify.com/CVE-2016-1448/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2016-1446](https://insights.sbomify.com/CVE-2016-1446/): SQL injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3126 and fix it if it is affected.

What it is: CVE-2020-3126 is a low-severity vulnerability in Cisco Webex Meetings Server, published on 13 Apr 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-3126 in the wild and no public exploit code.

Affected product: Cisco Webex Meetings Server. 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-2020-3126/ (Markdown: https://insights.sbomify.com/CVE-2020-3126/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3126
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3126
- OSV: https://osv.dev/vulnerability/CVE-2020-3126

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-3126/
Summaries are generated and may contain mistakes; the official description above is the record.