In all versions of PHP 7, during the unserialization process, resizing the 'properties' hash table of a serialized object may lead to use-after-free. A remote attacker may exploit this bug to gain arbitrary code execution.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| http://blog.checkpoint.com/wp-content/uploads/2016/12/PHP_Technical_Report.pdf | third party advisory exploit technical description |
| https://www.youtube.com/watch?v=LDcaPstAuPk | technical description |
| https://bugs.php.net/bug.php?id=73092 | issue tracking permissions required |
| https://access.redhat.com/errata/RHSA-2018:1296 | vendor advisory |
| https://security.netapp.com/advisory/ntap-20180112-0001/ | |
| http://www.securityfocus.com/bid/95151 | third party advisory vdb entry |
| http://www.securitytracker.com/id/1037659 | vdb entry |
| http://blog.checkpoint.com/2016/12/27/check-point-discovers-three-zero-day-vulnerabilities-web-programming-language-php-7 | third party advisory |