PHPCSUtils: Remote code execution via eval() in AbstractArrayDeclarationSniff::getActualArrayKey()

### Impact PHPCSUtils versions 1.0.0-alpha1 through 1.2.2 contain an arbitrary code execution vulnerability in `PHPCSUtils\AbstractSniffs\AbstractArrayDeclarationSniff::getActualArrayKey()`. The vulnerable method is reached by any sniff that extends `AbstractArrayDeclarationSniff` and calls `getActualArrayKey()`. Running PHPCS over untrusted PHP code through such a sniff, 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. The vulnerability happens when the method determines the value of an array key using `eval()`. A maliciously crafted array key such as `'system'('id')` would be executed when the code was scanned. ### Known attack vectors Known code paths that reach the vulnerable method include the following PHPCSExtra sniffs: - `Universal.Arrays.DuplicateArrayKey` - `Universal.Arrays.MixedArrayKeyTypes` Other packages that call `AbstractArrayDeclarationSniff::getActualArrayKey()` may also be vulnerable. ### Patches This issue has been fixed in PHPCSUtils 1.2.3. We recommend all users upgrade to 1.2.3 or later. ### Workaround Users who cannot upgrade immediately can disable the sniffs that reach the vulnerable method by adding `` tags to their custom ruleset (replace the placeholder standard and sniff names with the ones used in your setup): ```xml ``` For example, to disable the two PHPCSExtra sniffs listed under "Known attack vectors": ```xml ``` To v