Plug vulnerabilities

A vulnerability in the Elixir Plug library, specifically in the Plug.Conn.Cookies.encode/2 function, fails to neutralize the ';' delimiter in cookie attributes. This allows an attacker to inject additional attributes into the Set-Cookie header, potentially overriding existing cookie attributes.

The multipart parser in the Plug library does not count part headers against the :length budget, allowing an attacker to send a request with many empty-body file parts. Each part with a non-empty filename creates a temporary file, leading to inode, disk, and memory exhaustion. This enables an unauthenticated DoS attack.

Plug has an efficiency issue in the nested-parameter decoder that allows an unauthenticated remote attacker to cause denial of service. The decoding algorithm's complexity is quadratic in relation to the number of nesting levels, which can lead to server unresponsiveness.