# CVE-2007-1521: Use after free in n/a

> Attackers can execute arbitrary code by interrupting session regeneration in PHP, potentially compromising web applications using this library.

- **Severity:** Medium 6.8 (`AV:N/AC:M/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:** Yes
- **Published:** 20 Mar 2007
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-68q8-gr3h-67jh

## What is CVE-2007-1521?

CVE-2007-1521 is a medium-severity use after free vulnerability in Php Php, published on 20 Mar 2007. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Double free vulnerability in PHP before 4.4.7, and 5.x before 5.2.2, allows context-dependent attackers to execute arbitrary code by interrupting the session_regenerate_id function, as demonstrated by calling a userspace error handler or triggering a memory limit violation.

## Which versions are affected by CVE-2007-1521?

It affects 1 product.


Products: Php Php.

## How do I fix CVE-2007-1521?

Upgrade to a fixed version.

## Is CVE-2007-1521 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2007-1521 exists.

Public exploit code:

- PHP 5.2.1 - 'session_regenerate_id()' Double-Free (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-2007-1521 and fix it if it is affected.

What it is: CVE-2007-1521 is a medium-severity use after free vulnerability in Php Php, published on 20 Mar 2007. 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-2007-1521 exists.

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-2007-1521/ (Markdown: https://insights.sbomify.com/CVE-2007-1521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2007-1521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2007-1521
- OSV: https://osv.dev/vulnerability/CVE-2007-1521

---
From sbomify Insights: https://insights.sbomify.com/CVE-2007-1521/
Summaries are generated and may contain mistakes; the official description above is the record.