Affected are 2005 through 2009 Legacy and Outback, the 2008 through 2014 Impreza and the 2009 through 2013 Forester. It affects cars only in 20 states and Washington, DC, where salt is used to clear roads in the winter.
The company says in documents filed with the US government that salty water can splash onto the brake lines through a gap in the fuel tank protector, causing rust. If they leak fluid, it could take longer to stop the car and increase the risk of a crash.