# CVE-2019-1817: Cisco Web Security Appliance Malformed Request Denial of Service Vulnerability

> An unauthenticated remote attacker can cause a denial of service by sending malformed HTTP or HTTPS requests to the Cisco Web Security Appliance.

- **Severity:** High 8.6 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 May 2019
- **Updated:** 19 Nov 2024
- **Also known as:** GHSA-7577-f2mx-w9rc

## What is CVE-2019-1817?

CVE-2019-1817 is a high-severity denial of service vulnerability in Cisco Web Security Appliance, published on 3 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliance could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of HTTP and HTTPS requests. An attacker could exploit this vulnerability by sending a malformed HTTP or HTTPS request to an affected device. An exploit could allow the attacker to cause a restart of the web proxy process, resulting in a temporary DoS condition.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2019-1817?

It affects 1 product.


Products: Cisco Web Security Appliance.

## How do I fix CVE-2019-1817?

No fix has been published for CVE-2019-1817 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1817 being exploited?

There is no known exploitation of CVE-2019-1817 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Web Security Appliance

- [CVE-2015-6298](https://insights.sbomify.com/CVE-2015-6298/): Command injection in n/a (critical 9.0)
- [CVE-2018-0410](https://insights.sbomify.com/CVE-2018-0410/): Denial of service in AsyncOS Software for Cisco Web Security Appliances (high 8.6)
- [CVE-2015-6292](https://insights.sbomify.com/CVE-2015-6292/): Denial of service in n/a (high 7.8)
- [CVE-2015-6293](https://insights.sbomify.com/CVE-2015-6293/): Denial of service in n/a (high 7.8)
- [CVE-2018-0353](https://insights.sbomify.com/CVE-2018-0353/): Security feature bypass in Cisco Web Security Appliance unknown (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1817 and fix it if it is affected.

What it is: CVE-2019-1817 is a high-severity denial of service vulnerability in Cisco Web Security Appliance, published on 3 May 2019. 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-2019-1817 in the wild and no public exploit code.

Affected product: Cisco Web 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-2019-1817/ (Markdown: https://insights.sbomify.com/CVE-2019-1817/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1817
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1817
- OSV: https://osv.dev/vulnerability/CVE-2019-1817

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-1817/
Summaries are generated and may contain mistakes; the official description above is the record.