# CVE-2013-4123: Denial of service in n/a

> Remote attackers can cause a denial of service in Squid proxy servers by sending a crafted port number in the HTTP Host header.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2013
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-gpv8-rwm7-v9hg

## What is CVE-2013-4123?

CVE-2013-4123 is a medium-severity denial of service vulnerability in Opensuse Opensuse, published on 16 Sep 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

client_side_request.cc in Squid 3.2.x before 3.2.13 and 3.3.x before 3.3.8 allows remote attackers to cause a denial of service via a crafted port number in a HTTP Host header.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2013-4123?

It affects 2 products.


Products: Opensuse Opensuse, Squid-Cache Squid.

## How do I fix CVE-2013-4123?

Upgrade to a fixed version.

## Is CVE-2013-4123 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2013-4123 exists.

Public exploit code:

- Squid 3.3.5 - Denial of Service (PoC) (exploitdb)

## Other vulnerabilities in Opensuse Opensuse

- [CVE-2015-5957](https://insights.sbomify.com/CVE-2015-5957/): Memory corruption in n/a (critical 10.0)
- [CVE-2015-0491](https://insights.sbomify.com/CVE-2015-0491/): Memory corruption in n/a (critical 10.0)
- [CVE-2008-2388](https://insights.sbomify.com/CVE-2008-2388/): Integer overflow in n/a (critical 10.0)
- [CVE-2010-1866](https://insights.sbomify.com/CVE-2010-1866/): Integer overflow in n/a (critical 9.8)
- [CVE-2015-0492](https://insights.sbomify.com/CVE-2015-0492/): Other in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4123 and fix it if it is affected.

What it is: CVE-2013-4123 is a medium-severity denial of service vulnerability in Opensuse Opensuse, published on 16 Sep 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2013-4123 exists.

Affected product: Opensuse Opensuse. 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-2013-4123/ (Markdown: https://insights.sbomify.com/CVE-2013-4123/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4123
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4123
- OSV: https://osv.dev/vulnerability/CVE-2013-4123

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-4123/
Summaries are generated and may contain mistakes; the official description above is the record.