# CVE-2020-3164: Cisco ESA, Cisco WSA, and Cisco SMA GUI Denial of Service Vulnerability

> Unauthenticated remote attackers can cause high CPU usage and degrade performance on Cisco ESA, WSA, and SMA devices via malformed HTTP requests.

- **Severity:** Medium 5.3 (`CVSS:3.0/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:** 4 Mar 2020
- **Updated:** 15 Nov 2024
- **Also known as:** GHSA-2whj-38mw-g8jm

## What is CVE-2020-3164?

CVE-2020-3164 is a medium-severity denial of service vulnerability in Cisco Email Security Appliance, published on 4 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the web-based management interface of Cisco AsyncOS for Cisco Email Security Appliance (ESA), Cisco Web Security Appliance (WSA), and Cisco Content Security Management Appliance (SMA) could allow an unauthenticated remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of specific HTTP request headers. An attacker could exploit this vulnerability by sending a malformed HTTP request to an affected device. A successful exploit could allow the attacker to trigger a prolonged status of high CPU utilization relative to the GUI process(es). Upon successful exploitation of this vulnerability, an affected device will still be operative, but its response time and overall performance may be degraded.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-3164?

It affects 4 products.


Products: Cisco Cloud Email Security, Cisco Content Security Management Appliance, Cisco Email Security Appliance, Cisco Web Security Appliance.

## How do I fix CVE-2020-3164?

No fix has been published for CVE-2020-3164 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3164 being exploited?

There is no known exploitation of CVE-2020-3164 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Email Security Appliance

- [CVE-2020-3132](https://insights.sbomify.com/CVE-2020-3132/): Cisco Email Security Appliance Shortened URL Denial of Service Vulnerability (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3164 and fix it if it is affected.

What it is: CVE-2020-3164 is a medium-severity denial of service vulnerability in Cisco Email Security Appliance, published on 4 Mar 2020. 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-2020-3164 in the wild and no public exploit code.

Affected product: Cisco Email Security Appliance. 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-2020-3164/ (Markdown: https://insights.sbomify.com/CVE-2020-3164/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3164
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3164
- OSV: https://osv.dev/vulnerability/CVE-2020-3164

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-3164/
Summaries are generated and may contain mistakes; the official description above is the record.