# CVE-2015-8562: Deserialization in n/a

> Remote attackers can execute arbitrary PHP code via unsafe deserialization in the User-Agent header, requiring immediate upgrades.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Dec 2015
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-pccq-v233-rx3q

## What is CVE-2015-8562?

CVE-2015-8562 is a high-severity unsafe deserialization vulnerability in Joomla Joomla\!, published on 16 Dec 2015. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Joomla! 1.5.x, 2.x, and 3.x before 3.4.6 allow remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via the HTTP User-Agent header, as exploited in the wild in December 2015.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2015-8562?

It affects 1 product.


Products: Joomla Joomla\!.

## How do I fix CVE-2015-8562?

No fix has been published for CVE-2015-8562 yet. Limit exposure of the affected software until one is available.

## Is CVE-2015-8562 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2015-8562 exists.

Public exploit code:

- A proof of concept for Joomla's CVE-2015-8562 vulnerability (Object Injection RCE) (github_poc): https://github.com/VoidSec/Joomla_CVE-2015-8562
- All versions of the Joomla! below 3.4.6 are known to be vulnerable. But exploitation is possible with PHP versions below 5.5.29, 5.6.13 and below 5.5. (github_poc): https://github.com/ZaleHack/joomla_rce_CVE-2015-8562
- Joomla 1.5 - 3.4.5 Object Injection RCE X-Forwarded-For header (github_poc): https://github.com/dmonst3r/CVE-2015-8562
- A proof of concept for Joomla's CVE-2015-8562 vulnerability (github_poc): https://github.com/RobinHoutevelts/Joomla-CVE-2015-8562-PHP-POC
- https://github.com/Caihuar/Joomla-cve-2015-8562 (github_poc): https://github.com/Caihuar/Joomla-cve-2015-8562
- Joomla HTTP Header Unauthenticated Remote Code Execution (metasploit)

## Other vulnerabilities in Joomla Joomla\!

- [CVE-2016-10033](https://insights.sbomify.com/CVE-2016-10033/): PHPMailer Command Injection (critical 9.8, exploited in the wild)
- [CVE-2023-23752](https://insights.sbomify.com/CVE-2023-23752/): Joomla! Improper Access Control (medium 5.3, exploited in the wild)
- [CVE-2026-48902](https://insights.sbomify.com/CVE-2026-48902/): Joomla! Core - [20260518] - Transport encryption downgrade for password and username reset links (critical 9.8)
- [CVE-2025-25226](https://insights.sbomify.com/CVE-2025-25226/): [20250401] - Joomla Framework - SQL injection vulnerability in quoteNameStr method of Database package (critical 9.8)
- [CVE-2022-23795](https://insights.sbomify.com/CVE-2022-23795/): [20220303] - Core - User row are not bound to a authentication mechanism (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-8562 and fix it if it is affected.

What it is: CVE-2015-8562 is a high-severity unsafe deserialization vulnerability in Joomla Joomla\!, published on 16 Dec 2015. 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-2015-8562 exists.

Affected product: Joomla Joomla\!. 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-2015-8562/ (Markdown: https://insights.sbomify.com/CVE-2015-8562/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-8562
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-8562
- OSV: https://osv.dev/vulnerability/CVE-2015-8562

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-8562/
Summaries are generated and may contain mistakes; the official description above is the record.