# CVE-2023-20255: Denial of service in Cisco Meeting Server

> Unauthenticated remote attackers can cause denial of service in Cisco Meeting Server by sending crafted HTTP packets to the Web Bridge API.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Nov 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-mfw4-g24x-w66h

## What is CVE-2023-20255?

CVE-2023-20255 is a medium-severity denial of service vulnerability in Cisco Meeting Server, published on 1 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in an API of the Web Bridge feature of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to insufficient validation of HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP packets to an affected device. A successful exploit could allow the attacker to cause a partial availability condition, which could cause ongoing video calls to be dropped due to the invalid packets reaching the Web Bridge.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2023-20255?

It affects 1 product.


Products: Cisco Meeting Server.

## How do I fix CVE-2023-20255?

No fix has been published for CVE-2023-20255 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-20255 being exploited?

There is no known exploitation of CVE-2023-20255 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Meeting Server

- [CVE-2016-6448](https://insights.sbomify.com/CVE-2016-6448/): Memory corruption in Cisco Meeting Server before 2.0.3 and Acano Server before 1.9.5 (critical 9.8)
- [CVE-2017-12249](https://insights.sbomify.com/CVE-2017-12249/): Misconfiguration in Cisco Meeting Server (critical 9.1)
- [CVE-2016-6445](https://insights.sbomify.com/CVE-2016-6445/): Auth bypass in Cisco Meeting Server (CMS) before 2.0.6 and Acano Server before 1.8.18 and 1.9.x before 1.9.6 (critical 9.1)
- [CVE-2018-0439](https://insights.sbomify.com/CVE-2018-0439/): Cisco Meeting Server Cross-Site Request Forgery Vulnerability (high 8.8)
- [CVE-2016-6444](https://insights.sbomify.com/CVE-2016-6444/): Cross-site request forgery in Cisco Meeting Server 1.8, 1.9, 2.0 (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-20255 and fix it if it is affected.

What it is: CVE-2023-20255 is a medium-severity denial of service vulnerability in Cisco Meeting Server, published on 1 Nov 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-2023-20255 in the wild and no public exploit code.

Affected product: Cisco Meeting 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-2023-20255/ (Markdown: https://insights.sbomify.com/CVE-2023-20255/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-20255
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-20255
- OSV: https://osv.dev/vulnerability/CVE-2023-20255

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-20255/
Summaries are generated and may contain mistakes; the official description above is the record.