PHP DirectoryIterator class accepts filenames with embedded null byte and treats them as terminating at that byte

Publication Date2019-12-22
SeverityModerate
TypePrivilege Escalation
Affected PHP Versions
  • 7.2.0 - 7.2.25
  • 7.3.0 - 7.3.12
  • 7.4.0

CVE Details

In PHP versions 7.2.x below 7.2.26, 7.3.x below 7.3.13 and 7.4.0, PHP's DirectoryIterator class accepts filenames with embedded null bytes (\u0000) and treats them as terminating at that byte. This can lead to security vulnerabilities when applications check paths that the code is allowed to access.

Recommendations

Filter paths and filenames before providing them to the DirectoryIterator constructor:

preg_replace('/\\0/', "", $var);

When possible, update to PHP 7.2.26 or later, PH 7.3.13 or later, or 7.4.1 or later.