# CVE-2009-0801: Security feature bypass in n/a

> Remote attackers can bypass access controls and access restricted intranet sites via crafted HTTP requests when Squid is in transparent interception mode.

- **Severity:** Medium 5.4 (`AV:N/AC:H/Au:N/C:C/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 4 Mar 2009
- **Updated:** 17 Sep 2024
- **Also known as:** DEBIAN-CVE-2009-0801, GHSA-w87g-c2c7-4fx5

## What is CVE-2009-0801?

CVE-2009-0801 is a medium-severity vulnerability in n/a, published on 4 Mar 2009. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Squid, when transparent interception mode is enabled, uses the HTTP Host header to determine the remote endpoint, which allows remote attackers to bypass access controls for Flash, Java, Silverlight, and probably other technologies, and possibly communicate with restricted intranet sites, via a crafted web page that causes a client to send HTTP requests with a modified Host header.

Weakness: CWE-264

## Which versions are affected by CVE-2009-0801?

It affects 1 product.


Products: Squid Squid Web Proxy Cache.

## How do I fix CVE-2009-0801?

Apply the vendor's patch.

## Is CVE-2009-0801 being exploited?

There is no known exploitation of CVE-2009-0801 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2007-6239](https://insights.sbomify.com/CVE-2007-6239/): Denial of service in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-0801 and fix it if it is affected.

What it is: CVE-2009-0801 is a medium-severity vulnerability in n/a, published on 4 Mar 2009. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2009-0801 in the wild and no public exploit code.

Affected product: n/a. 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-2009-0801/ (Markdown: https://insights.sbomify.com/CVE-2009-0801/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-0801
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-0801
- OSV: https://osv.dev/vulnerability/CVE-2009-0801

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-0801/
Summaries are generated and may contain mistakes; the official description above is the record.