Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, PdoAdapter::doClear() builds a DELETE statement using a namespace derived from the caller-supplied $prefix without binding or escaping it, allowing a caller able to influence $prefix to break out of the LIKE literal and alter query semantics or deletion scope. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Affected: Packagist: symfony/cache, Packagist: symfony/symfony

### Description

`Symfony\Component\Cache\Adapter\PdoAdapter` is the PDO-backed cache adapter. Its `clear($prefix)` method (inherited from `AbstractAdapterTrait`) is documented to delete cache items whose key starts with `$prefix`.

In the non-versioning code path, the caller-supplied `$prefix` is concatenated into `$namespace = $this->namespace.$prefix` and passed to `PdoAdapter::doClear()`, which builds:

```sql DELETE FROM <table> WHERE <id_col> LIKE '<namespace>%' ```

The value is interpolated directly into the SQL text and executed with `PDO::exec()`: `$namespace` is not bound. A caller able to influence `$prefix` can break out of the literal and inject SQL, expanding deletion scope from the intended prefix to arbitrary rows, or otherwise reshape query semantics.

Most applications don't expose `clear($prefix)` to untrusted input directly, but the contract of the method is to safely accept any prefix string, so the lack of escaping is a defect of the adapter itself.

### Resolution

`AbstractAdapterTrait::clear()` now rejects any `$prefix` containing characters outside `[-+.A-Za-z0-9]`: when an invalid prefix is supplied, the method logs a warning and returns `false` instead of reaching the SQL layer. This blocks quotes, `%`, null bytes and other characters that would let an attacker break out of the `LIKE` literal.

The patch for this issue is available [here](https://github.com/symfony/symfony/commit/ec50b799d79ebe24561f29351c1efcb6da95c9b1) for branch 5.4.

### Cred…

Affected: Ubuntu:16.04:LTS: symfony, Ubuntu:Pro:18.04:LTS: symfony, Ubuntu:Pro:20.04:LTS: symfony, Ubuntu:Pro:22.04:LTS: symfony, Ubuntu:Pro:24.04:LTS: symfony, Ubuntu:25.10: symfony, Ubuntu:26.04:LTS: symfony

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, PdoAdapter::doClear() builds a DELETE statement using a namespace derived from the caller-supplied $prefix without binding or escaping it, allowing a caller able to influence $prefix to break out of the LIKE literal and alter query semantics or deletion scope. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.