# CVE-2009-4018: Security feature bypass in n/a

> Attackers can bypass PHP safe mode restrictions to execute arbitrary code with modified environment variables, requiring safe mode to be enabled.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Nov 2009
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-64wx-q8pj-gj2r

## What is CVE-2009-4018?

CVE-2009-4018 is a high-severity vulnerability in Php Php, published on 27 Nov 2009. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The proc_open function in ext/standard/proc_open.c in PHP before 5.2.11 and 5.3.x before 5.3.1 does not enforce the (1) safe_mode_allowed_env_vars and (2) safe_mode_protected_env_vars directives, which allows context-dependent attackers to execute programs with an arbitrary environment via the env parameter, as demonstrated by a crafted value of the LD_LIBRARY_PATH environment variable.

Weakness: CWE-264

## Which versions are affected by CVE-2009-4018?

It affects 1 product.


Products: Php Php.

## How do I fix CVE-2009-4018?

No fix has been published for CVE-2009-4018 yet. Limit exposure of the affected software until one is available.

## Is CVE-2009-4018 being exploited?

There is no known exploitation of CVE-2009-4018 in the wild and no public exploit code.

Public exploit code:

- Kolang 4.3.10 < 5.3.0 - 'proc_open()' PHP 'safe_mode' Bypass (exploitdb)

## Other vulnerabilities in Php Php

- [CVE-2012-2688](https://insights.sbomify.com/CVE-2012-2688/): Integer overflow in n/a (critical 10.0)
- [CVE-2012-2376](https://insights.sbomify.com/CVE-2012-2376/): Memory corruption in n/a (critical 10.0)
- [CVE-2011-3268](https://insights.sbomify.com/CVE-2011-3268/): Memory corruption in n/a (critical 10.0)
- [CVE-2009-4143](https://insights.sbomify.com/CVE-2009-4143/): Other in n/a (critical 10.0)
- [CVE-2008-5557](https://insights.sbomify.com/CVE-2008-5557/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2009-4018 and fix it if it is affected.

What it is: CVE-2009-4018 is a high-severity vulnerability in Php Php, published on 27 Nov 2009. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2009-4018 in the wild and no public exploit code.

Affected product: Php Php. 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-2009-4018/ (Markdown: https://insights.sbomify.com/CVE-2009-4018/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2009-4018
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2009-4018
- OSV: https://osv.dev/vulnerability/CVE-2009-4018

---
From sbomify Insights: https://insights.sbomify.com/CVE-2009-4018/
Summaries are generated and may contain mistakes; the official description above is the record.