Vulnerabilities in pkg:golang/https://github.com/dadrus/heimdall

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-38x9-25wx-7fg2",
  "modified" : "2026-07-20T21:28:51Z",
  "published" : "2026-06-18T14:24:37Z",
  "aliases" : [ "CVE-2026-57210" ],
  "summary" : "Heimdall: IP Spoofing via Unvalidated Forwarding Headers",
  "details" : "### Summary\n\nWhen the `trusted_proxies` option is configured, heimdall extracts client IP addresses from the `Forwarded` (`for=` parameter) and `X-Forwarded-For` headers and exposes them as `Request.ClientIPAddresses` to the rule pipeline. However, extracted values are not validated to be syntactically valid IP addresses. Arbitrary strings, malformed IP literals, and RFC 7239 `unknown` values and obfuscated identifiers are accepted without further checks.\nIn addition, the `Forwarded` header parser splits on `,` and `;` without accounting for RFC 7239 quoted strings, which can cause a single quoted value to be parsed as multiple entries, with fragments — including trailing quote characters — treated as independent addresses.\n\n### Impact\n\n`Request.ClientIPAddresses` is available to all pipeline mechanisms. Its contents can therefore influence rule evaluation in deployments where rules reference this property — for example, in a `CEL` authorizer that checks whether a request originates from a trusted IP range using the `networks()` function, or in a `Remote` authorizer that forwards the client IP as part of its payload to an external authorization system. Whether and how `Request.ClientIPAddresses` is used is entirely determined by the rule configuration.\n\nAdditionally, in proxy mode, `Request.ClientIPAddresses` is used directly to construct the `X-Forwarded-For` and `Forwarded` headers forwarded to upstream services. Injected or malformed values are therefore propagated to upstream services unchanged.\n\n### Attack Scenarios\n\nAll scenarios require that `trusted_proxies` is configured. If this option is not set, heimdall ignores forwarding headers entirely, and this vulnerability is not exploitable. Scenarios A and C  (see below) additionally require that rules reference `Request.ClientIPAddresses` in their pipeline.\n\n#### Scenario A – Manipulation of rule evaluation\n\nAn attacker who can influence forwarding headers — either by connecting directly to heimdall or through a proxy that does not sanitize these headers — can inject arbitrary values into `Request.ClientIPAddresses`. In deployments where a rule references this property (e.g. to restrict access to specific IP ranges), this may allow an attacker to bypass the intended access control logic.\n\n#### Scenario B – IP spoofing against upstream services (proxy mode)\n\nIn proxy mode, injected or malformed values in `Request.ClientIPAddresses` are written unchanged into the `X-Forwarded-For` header sent to upstream services. Upstream services that trust this header may therefore receive and act on attacker-controlled IP values.\n\n#### Scenario C – Malformed entries via quoted-string misparse\n\nA `Forwarded` header containing a quoted value with embedded delimiters (`,` or `;`) is misparsed, producing unintended additional entries in `Request.ClientIPAddresses`, including malformed fragments with trailing quote characters.\n\n### Workarounds\n\n* Ensure at the network level that only trusted proxies can communicate directly with heimdall.\n* Ensure that the proxy forwarding the requests to heimdall sanitizes or overrides (not merely appends to) `Forwarded` or `X-Forwarded-For` headers before forwarding them.\n* Avoid relying on `Request.ClientIPAddresses` for security-sensitive decisions until patched",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "https://github.com/dadrus/heimdall"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.17.17"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.17.16"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/dadrus/heimdall/security/advisories/GHSA-38x9-25wx-7fg2"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dadrus/heimdall"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-116", "CWE-20", "CWE-290" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-18T14:24:37Z",
    "nvd_published_at" : null
  }
}