# CVE-2018-1303: Denial of service in Apache HTTP Server

> A crafted HTTP request can crash Apache HTTP Server via an out-of-bounds read in mod_cache_socache, causing denial of service.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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:** Yes
- **Published:** 26 Mar 2018
- **Updated:** 17 Sep 2024
- **Also known as:** ALPINE-CVE-2018-1303, CLEANSTART-2026-MQ00302, DEBIAN-CVE-2018-1303, GHSA-8rrj-w45x-2fr2, UBUNTU-CVE-2018-1303

## What is CVE-2018-1303?

CVE-2018-1303 is a high-severity denial of service vulnerability in Apache Http Server, published on 26 Mar 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 due to an out of bound read while preparing data to be cached in shared memory. It could be used as a Denial of Service attack against users of mod_cache_socache. The vulnerability is considered as low risk since mod_cache_socache is not widely used, mod_cache_disk is not concerned by this vulnerability.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2018-1303?

It affects 7 products.


Products: Apache Http Server, Canonical Ubuntu Linux, Debian Debian Linux, Netapp Clustered Data Ontap, Netapp Santricity Cloud Connector, Netapp Storage Automation Store, Netapp Storagegrid.

## How do I fix CVE-2018-1303?

Upgrade to a fixed version.

## Is CVE-2018-1303 being exploited?

There is no known exploitation of CVE-2018-1303 in the wild and no public exploit code.

## Other vulnerabilities in Apache Http Server

- [CVE-2021-42013](https://insights.sbomify.com/CVE-2021-42013/): Apache HTTP Server Path Traversal (critical 9.8, exploited in the wild)
- [CVE-2024-38475](https://insights.sbomify.com/CVE-2024-38475/): Apache HTTP Server Improper Escaping of Output (critical 9.1, exploited in the wild)
- [CVE-2021-40438](https://insights.sbomify.com/CVE-2021-40438/): Apache HTTP Server-Side Request Forgery (SSRF) (critical 9.0, exploited in the wild)
- [CVE-2019-0211](https://insights.sbomify.com/CVE-2019-0211/): Apache HTTP Server Privilege Escalation (high 7.8, exploited in the wild)
- [CVE-2021-41773](https://insights.sbomify.com/CVE-2021-41773/): Apache HTTP Server Path Traversal (high 7.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1303 and fix it if it is affected.

What it is: CVE-2018-1303 is a high-severity denial of service vulnerability in Apache Http Server, published on 26 Mar 2018. 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-2018-1303 in the wild and no public exploit code.

Affected product: Apache Http 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-2018-1303/ (Markdown: https://insights.sbomify.com/CVE-2018-1303/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1303
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1303
- OSV: https://osv.dev/vulnerability/CVE-2018-1303

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1303/
Summaries are generated and may contain mistakes; the official description above is the record.