FKIE_CVE-2026-72889

Vulnerability from fkie_nvd - Published: 2026-08-19 08:17 - Updated: 2026-08-26 19:17
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verify. verify resolves the signature method class from the signature_method parameter of the incoming message. signature_method is required on every request, so the algorithm used to check a signature is chosen by whoever sent it, and nothing lets the verifying party pin the method instead. When a message names HMAC-SHA1 or HMAC-SHA256, the key is derived from consumer_secret and token_secret rather than from the key the provider deployed. A provider deployed on RSA-SHA1 holds only the consumer public key, and RFC 5849 does not use consumer_secret for that method, so the required parameter is filled with a placeholder. A client that names HMAC-SHA1 instead has its signature checked against that placeholder, so a guessable one is enough to forge requests for any consumer key and token.
References
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://datatracker.ietf.org/doc/html/rfc5849#section-3.4.2
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://datatracker.ietf.org/doc/html/rfc5849#section-3.4.3
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://github.com/vurtdev/Net-OAuth/commit/c467adf45c8d77ac4b92ad78b3eebf949252ba7f.patch
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://github.com/vurtdev/Net-OAuth/security/advisories/GHSA-c8rm-g5cm-4pf5
9b29abf9-4ab0-4765-b253-1875cd9b441ehttps://metacpan.org/release/RRWO/Net-OAuth-0.33/changes
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/08/19/2
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Net::OAuth"
          ],
          "packageName": "Net-OAuth",
          "packageURL": "pkg:cpan/Net-OAuth",
          "programFiles": [
            "lib/Net/OAuth/Message.pm",
            "lib/Net/OAuth/Request.pm"
          ],
          "programRoutines": [
            {
              "name": "Net::OAuth::Message::verify"
            },
            {
              "name": "Net::OAuth::Message::_signature_method_class"
            },
            {
              "name": "Net::OAuth::Request::signature_key"
            }
          ],
          "repo": "https://github.com/vurtdev/Net-OAuth",
          "versions": [
            {
              "lessThan": "0.33",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verify.\n\nverify resolves the signature method class from the signature_method parameter of the incoming message. signature_method is required on every request, so the algorithm used to check a signature is chosen by whoever sent it, and nothing lets the verifying party pin the method instead. When a message names HMAC-SHA1 or HMAC-SHA256, the key is derived from consumer_secret and token_secret rather than from the key the provider deployed.\n\nA provider deployed on RSA-SHA1 holds only the consumer public key, and RFC 5849 does not use consumer_secret for that method, so the required parameter is filled with a placeholder. A client that names HMAC-SHA1 instead has its signature checked against that placeholder, so a guessable one is enough to forge requests for any consumer key and token."
    }
  ],
  "id": "CVE-2026-72889",
  "lastModified": "2026-08-26T19:17:00.557",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-72889",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-26T18:02:49.745063Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-19T08:17:13.833",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://datatracker.ietf.org/doc/html/rfc5849#section-3.4.2"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://datatracker.ietf.org/doc/html/rfc5849#section-3.4.3"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/vurtdev/Net-OAuth/commit/c467adf45c8d77ac4b92ad78b3eebf949252ba7f.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/vurtdev/Net-OAuth/security/advisories/GHSA-c8rm-g5cm-4pf5"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/RRWO/Net-OAuth-0.33/changes"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/08/19/2"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-347"
        },
        {
          "lang": "en",
          "value": "CWE-757"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}



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