GHSA-CMM3-54F8-PX4J

Vulnerability from github – Published: 2026-06-08 22:59 – Updated: 2026-06-12 19:29
VLAI
Summary
Netty's Default QUIC token handler accepts any client-supplied token
Details

NoQuicTokenHandler is the tokenHandler used when the application does not set one. Its writeToken() returns false (server will not send Retry — acceptable), but validateToken() unconditionally return 0. In QuicheQuicServerCodec.handlePacket(), a non-negative return from validateToken() is interpreted as 'token is valid, ODCID starts at offset 0', causing the server to call quiche_accept as if the client's address had been validated by a Retry round-trip. Per RFC 9000 §8.1, a validated address lifts the 3× anti-amplification send limit. Thus any attacker who includes ANY non-empty token bytes in an Initial packet — with a spoofed victim source IP — causes the Netty server to treat the victim as validated and reflect full-size handshake flights (certificates, etc.) toward it without the 3× cap. The correct 'no token handler' semantics would be to return -1 (invalid) so the normal un-validated path and amplification limit apply.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.14.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-classes-quic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.15.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44894"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-940"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-08T22:59:43Z",
    "nvd_published_at": "2026-06-12T15:16:26Z",
    "severity": "HIGH"
  },
  "details": "NoQuicTokenHandler is the tokenHandler used when the application does not set one. Its writeToken() returns false (server will not send Retry \u2014 acceptable), but validateToken() unconditionally `return 0`. In QuicheQuicServerCodec.handlePacket(), a non-negative return from validateToken() is interpreted as \u0027token is valid, ODCID starts at offset 0\u0027, causing the server to call quiche_accept as if the client\u0027s address had been validated by a Retry round-trip. Per RFC 9000 \u00a78.1, a validated address lifts the 3\u00d7 anti-amplification send limit. Thus any attacker who includes ANY non-empty token bytes in an Initial packet \u2014 with a spoofed victim source IP \u2014 causes the Netty server to treat the victim as validated and reflect full-size handshake flights (certificates, etc.) toward it without the 3\u00d7 cap. The correct \u0027no token handler\u0027 semantics would be to return -1 (invalid) so the normal un-validated path and amplification limit apply.",
  "id": "GHSA-cmm3-54f8-px4j",
  "modified": "2026-06-12T19:29:17Z",
  "published": "2026-06-08T22:59:43Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-cmm3-54f8-px4j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44894"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Netty\u0027s Default QUIC token handler accepts any client-supplied token"
}


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