FKIE_CVE-2026-75628

Vulnerability from fkie_nvd - Published: 2026-08-20 01:16 - Updated: 2026-08-20 03:16
Severity
Summary
Punk::OAuth2 versions before 0.03 for Perl allow an attacker-chosen off-site redirect after login because same_origin_path accepts a backslash or tab in the return parameter. oauth2_login reads the return parameter from the initiation request, runs same_origin_path over it, and stores the survivor in the session flow record as the post-login redirect target. That check rejects a value that does not begin with a slash, one with a slash as its second byte, and one containing CR or LF. A backslash and a tab pass. The URL Standard treats a backslash as equivalent to a slash for special schemes, so `/\evil.example` parses with the authority `evil.example`. It also strips ASCII tab before parsing, so a tab between two leading slashes leaves `//evil.example`. A crafted link to the application's own login route lands the victim on the attacker's site after a genuine authentication. The redirect carries no authorization code or access token.
References
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://datatracker.ietf.org/doc/html/rfc9700#section-4.11.1
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://metacpan.org/release/LNATION/Punk-OAuth2-0.02/source/include/pox/pox_util.h#L94
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://metacpan.org/release/LNATION/Punk-OAuth2-0.03/changes
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://url.spec.whatwg.org/#concept-basic-url-parser
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://url.spec.whatwg.org/#relative-slash-state
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/08/20/1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Punk::OAuth2"
          ],
          "packageName": "Punk-OAuth2",
          "packageURL": "pkg:cpan/Punk-OAuth2",
          "programFiles": [
            "include/pox/pox_util.h",
            "lib/Punk/Plugin/OAuth2.pm"
          ],
          "programRoutines": [
            {
              "name": "Punk::OAuth2::same_origin_path"
            }
          ],
          "versions": [
            {
              "lessThan": "0.03",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Punk::OAuth2 versions before 0.03 for Perl allow an attacker-chosen off-site redirect after login because same_origin_path accepts a backslash or tab in the return parameter.\n\noauth2_login reads the return parameter from the initiation request, runs same_origin_path over it, and stores the survivor in the session flow record as the post-login redirect target. That check rejects a value that does not begin with a slash, one with a slash as its second byte, and one containing CR or LF. A backslash and a tab pass. The URL Standard treats a backslash as equivalent to a slash for special schemes, so `/\\evil.example` parses with the authority `evil.example`. It also strips ASCII tab before parsing, so a tab between two leading slashes leaves `//evil.example`.\n\nA crafted link to the application\u0027s own login route lands the victim on the attacker\u0027s site after a genuine authentication. The redirect carries no authorization code or access token."
    }
  ],
  "id": "CVE-2026-75628",
  "lastModified": "2026-08-20T03:16:23.340",
  "metrics": {},
  "published": "2026-08-20T01:16:53.803",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://datatracker.ietf.org/doc/html/rfc9700#section-4.11.1"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/LNATION/Punk-OAuth2-0.02/source/include/pox/pox_util.h#L94"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/LNATION/Punk-OAuth2-0.03/changes"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://url.spec.whatwg.org/#concept-basic-url-parser"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://url.spec.whatwg.org/#relative-slash-state"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/08/20/1"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-601"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}



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