oss-sec mailing list archives
Re: CVE Request: PHP with Zend OPCache code permission/sensitive data protection vulnerability
From: php-dev () coydogsoftware net
Date: Tue, 28 Feb 2017 05:08:06 -0600
On Mon, Feb 27, 2017 at 04:52:58PM -0600, php-dev () coydogsoftware net wrote:
To briefly summarize, in PHP SAPI's where PHP interpreters share a common parent process (eg. Apache mod_php and PHP-FPM), 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. In these scenarios, 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. AFFECTED VERSIONS: PHP7 < 7.0.14 and PHP5 < 5.6.29. Later versions are still vulnerable by default unless opcache.validate_permission=1 is enabled. AFFECTED COMPONENT: Zend OpCache VULNERABILITY TYPE: Code permission/sensitive information disclosure IMPACT: Cross-user compromise of PHP web applications in shared hosting environments. REFERENCES: http://marc.info/?l=php-internals&m=147921016724565&w=2 https://bugs.php.net/bug.php?id=69090 http://seclists.org/oss-sec/2016/q4/343
This has been assigned CVE-2015-8994 via cveform.mitre.org. -- php-dev at coydogsoftware dot net
Current thread:
- CVE Request: PHP with Zend OPCache code permission/sensitive data protection vulnerability php-dev (Feb 27)
- Re: CVE Request: PHP with Zend OPCache code permission/sensitive data protection vulnerability php-dev (Feb 28)