Impact
WordPress Coding Standards (WordPressCS) versions before 3.4.1 contain an arbitrary code execution vulnerability in the WordPress.WP.EnqueuedResourceParameters sniff. As a result, running PHPCS with WordPressCS over untrusted PHP code, for example, in a CI pipeline that lints pull requests, or on a developer machine reviewing third-party code, could lead to arbitrary command execution on the scanning host.
This affects users of the WordPress and WordPress-Extra rulesets. The WordPress-Core ruleset and the WordPress-Docs ruleset are not affected.
The vulnerability happens when the sniff checks whether the $var argument passed to functions such as wp_enqueue_script() or wp_register_script() evaluates to a falsy value. The sniff's is_falsy() method reconstructed the argument and ran it through eval(). Because of this, a maliciously crafted $ver argument such as 'system'('id') would be executed during the scan.
Patches
This issue has been fixed in WordPressCS 3.4.1. We recommend all users upgrade to 3.4.1 or later.
Workaround
Users of the WordPress and WordPress-Extra rulesets, who cannot upgrade immediately, can disable the affected sniff by adding an <exclude> tag to their custom ruleset (the <rule> ref value might vary depending on the ruleset):
<rule ref="WordPress">
<exclude name="WordPress.WP.EnqueuedResourceParameters"/>
</rule>
To verify that the sniff has been disabled, run PHPCS with the -e flag, which lists all the sniffs a standard will run. WordPress.WP.EnqueuedResourceParameters should no longer appear in the output under the WordPress section:
phpcs -e --standard=/path/to/ruleset.xml
Credits
Many thanks to @FORIMOC for responsibly disclosing this vulnerability.
How can I report a security bug?
Please report security vulnerabilities privately via the "Security and quality" tab on the WPCS repository.
References
FORIMOC Finder
rodrigoprimo Remediation developer
jrfnl Remediation reviewer
Impact
WordPress Coding Standards (WordPressCS) versions before 3.4.1 contain an arbitrary code execution vulnerability in the
WordPress.WP.EnqueuedResourceParameterssniff. As a result, running PHPCS with WordPressCS over untrusted PHP code, for example, in a CI pipeline that lints pull requests, or on a developer machine reviewing third-party code, could lead to arbitrary command execution on the scanning host.This affects users of the
WordPressandWordPress-Extrarulesets. TheWordPress-Coreruleset and theWordPress-Docsruleset are not affected.The vulnerability happens when the sniff checks whether the
$varargument passed to functions such aswp_enqueue_script()orwp_register_script()evaluates to a falsy value. The sniff'sis_falsy()method reconstructed the argument and ran it througheval(). Because of this, a maliciously crafted$verargument such as'system'('id')would be executed during the scan.Patches
This issue has been fixed in WordPressCS 3.4.1. We recommend all users upgrade to 3.4.1 or later.
Workaround
Users of the
WordPressandWordPress-Extrarulesets, who cannot upgrade immediately, can disable the affected sniff by adding an<exclude>tag to their custom ruleset (the<rule>refvalue might vary depending on the ruleset):To verify that the sniff has been disabled, run PHPCS with the
-eflag, which lists all the sniffs a standard will run.WordPress.WP.EnqueuedResourceParametersshould no longer appear in the output under theWordPresssection:Credits
Many thanks to @FORIMOC for responsibly disclosing this vulnerability.
How can I report a security bug?
Please report security vulnerabilities privately via the "Security and quality" tab on the WPCS repository.
References