FKIE_CVE-2025-13591

Vulnerability from fkie_nvd - Published: 2026-10-19 17:16 - Updated: 2026-10-19 21:06
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Summary
The authentication endpoint of WSO2 Identity Server fails to provide a consistent system response when a username does not exist in the system, allowing attackers to differentiate between valid and invalid usernames. This difference in responses can be leveraged to enumerate existing user accounts. Successful exploitation enables an attacker to discover valid usernames within the system, significantly increasing the risk of subsequent attacks such as brute force attacks on user credentials, social engineering attacks, and information leakage. The discovered usernames can be used to craft targeted phishing emails or other social engineering campaigns.
References
ed10eef1-636d-4fbe-9993-6890dfa878f8https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4583/
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "WSO2 Identity Server",
          "vendor": "WSO2",
          "versions": [
            {
              "lessThan": "7.0.0",
              "status": "unknown",
              "version": "0",
              "versionType": "custom"
            },
            {
              "lessThan": "7.0.0.134",
              "status": "affected",
              "version": "7.0.0",
              "versionType": "custom"
            },
            {
              "lessThan": "7.1.0.42",
              "status": "affected",
              "version": "7.1.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "packageName": "org.wso2.carbon.identity.auth.otp.commons:org.wso2.carbon.identity.auth.otp.core",
          "product": "WSO2 Carbon Abstract OTP Authenticator",
          "vendor": "WSO2",
          "versions": [
            {
              "lessThan": "1.0.5.3",
              "status": "affected",
              "version": "1.0.5",
              "versionType": "custom"
            },
            {
              "lessThan": "1.0.10.2",
              "status": "affected",
              "version": "1.0.10",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "packageName": "org.wso2.carbon.identity.local.auth.emailotp:org.wso2.carbon.identity.local.auth.emailotp",
          "product": "Email OTP Authenticator",
          "vendor": "WSO2",
          "versions": [
            {
              "lessThan": "1.0.18.8",
              "status": "affected",
              "version": "1.0.18",
              "versionType": "custom"
            },
            {
              "lessThan": "1.0.30.5",
              "status": "affected",
              "version": "1.0.30",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The authentication endpoint of WSO2 Identity Server fails to provide a consistent system response when a username does not exist in the system, allowing attackers to differentiate between valid and invalid usernames. This difference in responses can be leveraged to enumerate existing user accounts.\n\nSuccessful exploitation enables an attacker to discover valid usernames within the system, significantly increasing the risk of subsequent attacks such as brute force attacks on user credentials, social engineering attacks, and information leakage. The discovered usernames can be used to craft targeted phishing emails or other social engineering campaigns."
    }
  ],
  "id": "CVE-2025-13591",
  "lastModified": "2026-10-19T21:06:28.507",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-19T17:16:59.413",
  "references": [
    {
      "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
      "url": "https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2025-4583/"
    }
  ],
  "sourceIdentifier": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-203"
        }
      ],
      "source": "ed10eef1-636d-4fbe-9993-6890dfa878f8",
      "type": "Secondary"
    }
  ]
}



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