FKIE_CVE-2021-27850

Vulnerability from fkie_nvd - Published: 2021-04-15 08:15 - Updated: 2024-11-21 05:58
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
A critical unauthenticated remote code execution vulnerability was found all recent versions of Apache Tapestry. The affected versions include 5.4.5, 5.5.0, 5.6.2 and 5.7.0. The vulnerability I have found is a bypass of the fix for CVE-2019-0195. Recap: Before the fix of CVE-2019-0195 it was possible to download arbitrary class files from the classpath by providing a crafted asset file URL. An attacker was able to download the file `AppModule.class` by requesting the URL `http://localhost:8080/assets/something/services/AppModule.class` which contains a HMAC secret key. The fix for that bug was a blacklist filter that checks if the URL ends with `.class`, `.properties` or `.xml`. Bypass: Unfortunately, the blacklist solution can simply be bypassed by appending a `/` at the end of the URL: `http://localhost:8080/assets/something/services/AppModule.class/` The slash is stripped after the blacklist check and the file `AppModule.class` is loaded into the response. This class usually contains the HMAC secret key which is used to sign serialized Java objects. With the knowledge of that key an attacker can sign a Java gadget chain that leads to RCE (e.g. CommonsBeanUtils1 from ysoserial). Solution for this vulnerability: * For Apache Tapestry 5.4.0 to 5.6.1, upgrade to 5.6.2 or later. * For Apache Tapestry 5.7.0, upgrade to 5.7.1 or later.
References
security@apache.orghttp://www.openwall.com/lists/oss-security/2021/04/15/1Exploit, Mailing List, Third Party Advisory
security@apache.orghttps://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3EMailing List, Vendor Advisory
security@apache.orghttps://security.netapp.com/advisory/ntap-20210528-0002/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/04/15/1Exploit, Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3EMailing List, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20210528-0002/Third Party Advisory
Impacted products
Vendor Product Version
apache tapestry *
apache tapestry *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:apache:tapestry:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5611789E-E882-49FF-9E33-A8612A394FE5",
              "versionEndExcluding": "5.6.2",
              "versionStartIncluding": "5.4.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:apache:tapestry:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "4709FF63-6606-413B-941E-3E58DDA96203",
              "versionEndExcluding": "5.7.1",
              "versionStartIncluding": "5.7.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A critical unauthenticated remote code execution vulnerability was found all recent versions of Apache Tapestry. The affected versions include 5.4.5, 5.5.0, 5.6.2 and 5.7.0. The vulnerability I have found is a bypass of the fix for CVE-2019-0195. Recap: Before the fix of CVE-2019-0195 it was possible to download arbitrary class files from the classpath by providing a crafted asset file URL. An attacker was able to download the file `AppModule.class` by requesting the URL `http://localhost:8080/assets/something/services/AppModule.class` which contains a HMAC secret key. The fix for that bug was a blacklist filter that checks if the URL ends with `.class`, `.properties` or `.xml`. Bypass: Unfortunately, the blacklist solution can simply be bypassed by appending a `/` at the end of the URL: `http://localhost:8080/assets/something/services/AppModule.class/` The slash is stripped after the blacklist check and the file `AppModule.class` is loaded into the response. This class usually contains the HMAC secret key which is used to sign serialized Java objects. With the knowledge of that key an attacker can sign a Java gadget chain that leads to RCE (e.g. CommonsBeanUtils1 from ysoserial). Solution for this vulnerability: * For Apache Tapestry 5.4.0 to 5.6.1, upgrade to 5.6.2 or later. * For Apache Tapestry 5.7.0, upgrade to 5.7.1 or later."
    },
    {
      "lang": "es",
      "value": "Se encontr\u00f3 una vulnerabilidad cr\u00edtica de ejecuci\u00f3n de c\u00f3digo remota no autenticado en todas las versiones recientes de Apache Tapestry.\u0026#xa0;Las versiones afectadas incluyen 5.4.5, 5.5.0, 5.6.2 y 5.7.0.\u0026#xa0;La vulnerabilidad encontrada es un desv\u00edo de la soluci\u00f3n para CVE-2019-0195.\u0026#xa0;Resumen: versiones anteriores a correcci\u00f3n de CVE-2019-0195, era posible descargar archivos de clases arbitrarios desde la ruta de clases proporcionando una URL de archivo de activos dise\u00f1ada.\u0026#xa0;Un atacante pudo descargar el archivo \"AppModule.class\" al requerir la URL \"http://localhost:8080/assets/something/services/AppModule.class\" que contiene una clave secreta HMAC.\u0026#xa0;La correcci\u00f3n para ese error fue un filtro de lista negra que verifica si la URL termina con \".class\",\" properties\" o \".xml\".\u0026#xa0;Omitir: Desafortunadamente, la soluci\u00f3n de lista negra puede simplemente ser omitida al agregar un \"/` al final de la URL: \"http: // localhost:8080/assets/something/services/AppModule.class/\". La barra es eliminada despu\u00e9s de la comprobaci\u00f3n de la lista negra y el archivo` AppModule.class` se carga en la respuesta.\u0026#xa0;Esta clase generalmente contiene la clave secreta HMAC que es usada para firmar objetos Java serializados.\u0026#xa0;Con el conocimiento de esa clave, un atacante puede firmar una cadena de dispositivos Java que conlleva a una RCE (por ejemplo, CommonsBeanUtils1 de ysoserial).\u0026#xa0;Soluci\u00f3n para esta vulnerabilidad: *Para Apache Tapestry versiones 5.4.0 hasta 5.6.1, actualice a versiones 5.6.2 o posteriores.\u0026#xa0;*Para Apache Tapestry versi\u00f3n 5.7.0, actualice a versiones 5.7.1 o posteriores"
    }
  ],
  "id": "CVE-2021-27850",
  "lastModified": "2024-11-21T05:58:38.010",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "COMPLETE",
          "baseScore": 10.0,
          "confidentialityImpact": "COMPLETE",
          "integrityImpact": "COMPLETE",
          "vectorString": "AV:N/AC:L/Au:N/C:C/I:C/A:C",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 10.0,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "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": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-04-15T08:15:14.823",
  "references": [
    {
      "source": "security@apache.org",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/04/15/1"
    },
    {
      "source": "security@apache.org",
      "tags": [
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      "url": "https://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3E"
    },
    {
      "source": "security@apache.org",
      "tags": [
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      ],
      "url": "https://security.netapp.com/advisory/ntap-20210528-0002/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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      "url": "http://www.openwall.com/lists/oss-security/2021/04/15/1"
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    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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      "url": "https://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3E"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://security.netapp.com/advisory/ntap-20210528-0002/"
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  ],
  "sourceIdentifier": "security@apache.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-200"
        },
        {
          "lang": "en",
          "value": "CWE-502"
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      "source": "security@apache.org",
      "type": "Secondary"
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    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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Detection rules are retrieved from Rulezet.