# CVE-2018-20148: Deserialization in n/a

> Contributors can execute arbitrary PHP code via crafted metadata in XMLRPC calls due to unsafe deserialization of phar URLs.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 14 Dec 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-20148, GHSA-jgj7-cghf-2wq9, UBUNTU-CVE-2018-20148

## What is CVE-2018-20148?

CVE-2018-20148 is a critical unsafe deserialization vulnerability in Debian Debian Linux, published on 14 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In WordPress before 4.9.9 and 5.x before 5.0.1, contributors could conduct PHP object injection attacks via crafted metadata in a wp.getMediaItem XMLRPC call. This is caused by mishandling of serialized data at phar:// URLs in the wp_get_attachment_thumb_file function in wp-includes/post.php.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2018-20148?

It affects 2 products.


Products: Debian Debian Linux, Wordpress Wordpress.

## How do I fix CVE-2018-20148?

Upgrade to a fixed version.

## Is CVE-2018-20148 being exploited?

There is no known exploitation of CVE-2018-20148 in the wild and no public exploit code.

Public exploit code:

- Exploit for CVE-2018-20148 - WordPress PHAR deserialization via XMLRPC (github_poc): https://github.com/nth347/CVE-2018-20148_exploit

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20148 and fix it if it is affected.

What it is: CVE-2018-20148 is a critical unsafe deserialization vulnerability in Debian Debian Linux, published on 14 Dec 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-2018-20148 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2018-20148/ (Markdown: https://insights.sbomify.com/CVE-2018-20148/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20148
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20148
- OSV: https://osv.dev/vulnerability/CVE-2018-20148

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20148/
Summaries are generated and may contain mistakes; the official description above is the record.