|Date: (C)2006-10-10 (M)2017-07-21|
|CVSS Score: 6.2||Access Vector: LOCAL|
|Exploitability Subscore: 1.9||Access Complexity: HIGH|
|Impact Subscore: 10.0||Authentication: NONE|
| ||Confidentiality: COMPLETE|
| ||Integrity: COMPLETE|
| ||Availability: COMPLETE|
Race condition in the symlink function in PHP 5.1.6 and earlier allows local users to bypass the open_basedir restriction by using a combination of symlink, mkdir, and unlink functions to change the file path after the open_basedir check and before the file is opened by the underlying system, as demonstrated by symlinking a symlink into a subdirectory, to point to a parent directory via .. (dot dot) sequences, and then unlinking the resulting symlink.