{"id":"CVE-2025-24898","aliases":["GHSA-rpmj-rpgj-qmpm","RUSTSEC-2025-0004"],"url":"https://o3.security/vulnerability/CVE-2025-24898","summary":"rust openssl ssl::select_next_proto use after free","details":"### Impact\n`ssl::select_next_proto` can return a slice pointing into the `server` argument's buffer but with a lifetime bound to the `client` argument. In situations where the `server` buffer's lifetime is shorter than the `client` buffer's, this can cause a use after free. This could cause the server to crash or to return arbitrary memory contents to the client.\n\n### Patches\n`openssl` 0.10.70 fixes the signature of `ssl::select_next_proto` to properly constrain the output buffer's lifetime to that of both input buffers.\n\n### Workarounds\nIn standard usage of `ssl::select_next_proto` in the callback passed to `SslContextBuilder::set_alpn_select_callback`, code is only affected if the `server` buffer is constructed *within* the callback. For example:\n\nNot vulnerable - the server buffer has a `'static` lifetime:\n```rust\nbuilder.set_alpn_select_callback(|_, client_protos| {\n    ssl::select_next_proto(b\"\\x02h2\", client_protos).ok_or_else(AlpnError::NOACK)\n});\n```\n\nNot vulnerable - the server buffer outlives the handshake:\n```rust\nlet server_protos = b\"\\x02h2\".to_vec();\nbuilder.set_alpn_select_callback(|_, client_protos| {\n    ssl::select_next_proto(&server_protos, client_protos).ok_or_else(AlpnError::NOACK)\n});\n```\n\nVulnerable - the server buffer is freed when the callback returns:\n```rust\nbuilder.set_alpn_select_callback(|_, client_protos| {\n    let server_protos = b\"\\x02h2\".to_vec();\n    ssl::select_next_proto(&server_protos, client_protos).ok_or_else(AlpnError::NOACK)\n});\n```\n\n### References\nhttps://github.com/sfackler/rust-openssl/pull/2360","published":"2025-02-03T17:57:39.558Z","modified":"2026-08-14T18:51:41.858859472Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"openssl","fixedVersion":"0.10.70"}],"fix":{"url":"https://github.com/sfackler/rust-openssl/pull/2360","label":"sfackler/rust-openssl#2360"},"references":[{"type":"WEB","url":"https://crates.io/crates/openssl"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/02/msg00009.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/24xxx/CVE-2025-24898.json"},{"type":"ADVISORY","url":"https://github.com/sfackler/rust-openssl/security/advisories/GHSA-rpmj-rpgj-qmpm"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-24898"},{"type":"FIX","url":"https://github.com/sfackler/rust-openssl/pull/2360"},{"type":"WEB","url":"https://github.com/sfackler/rust-openssl/commit/f014afb230de4d77bc79dea60e7e58c2f47b60f2"},{"type":"PACKAGE","url":"https://github.com/sfackler/rust-openssl"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2025-0004.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-14T18:51:41.858859472Z"}}