ssl::select_next_proto use after free

{
  "id": "7313123958d569714cba69b341e5f9f375d5fb7e05d7d432753ec98881d2454b",
  "url": "https://osv.dev/vulnerability/RUSTSEC-2025-0004",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ssl::select_next_proto use after free",
    "summary": "In `openssl` versions before `0.10.70`, `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. `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. In 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: Not vulnerable - the server buffer has a `'static` lifetime: ```rust builder.set_alpn_select_callback(|_, client_protos| { ssl::select_next_proto(b\"\\x02h2\", client_protos).ok_or_else(AlpnError::NOACK) }); ``` Not vulnerable - the server buffer outlives the handshake: ```rust let server_protos = b\"\\x02h2\".to_vec(); builder.set_alpn_select_callback(|_, client_protos| { ssl::select_next_proto(&server_protos, client_protos).ok_or_else(AlpnError::NOACK) }); ``` Vulnerable - the server buffer is freed when the callback returns: ```rust builder.set_alpn_select_callback(|_, client_protos| { let server_protos = b\"\\x02h2\".to_vec(); ssl::select_next_proto(&server_protos, client_protos).ok_or_else(AlpnError::NOACK) }); ```",
    "evidence": "osv:RUSTSEC-2025-0004",
    "products": [
      {
        "name": {
          "value": "openssl",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "0.10.70",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "RUSTSEC-2025-0004",
      "aliases": [
        "CVE-2025-24898",
        "GHSA-rpmj-rpgj-qmpm",
        "RUSTSEC-2025-0004"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.0.0-0"
                },
                {
                  "fixed": "0.10.70"
                }
              ]
            }
          ],
          "package": {
            "name": "openssl",
            "purl": "pkg:cargo/openssl",
            "ecosystem": "crates.io"
          },
          "database_specific": {
            "cvss": null,
            "source": "https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2025-0004.json",
            "categories": [
              "memory-exposure"
            ],
            "informational": null
          },
          "ecosystem_specific": {
            "affects": {
              "os": [],
              "arch": [],
              "functions": [
                "openssl::ssl::select_next_proto"
              ]
            },
            "affected_functions": null
          }
        }
      ],
      "modified": "2026-10-12T18:00:12.406916247Z",
      "provider": "osv",
      "references": [
        "https://crates.io/crates/openssl",
        "https://rustsec.org/advisories/RUSTSEC-2025-0004.html",
        "https://github.com/sfackler/rust-openssl/pull/2360"
      ],
      "provider_metadata": {
        "license": "CC0-1.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-24898",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 306432,
  "published_at": "2025-02-02T12:00:00+00:00"
}