fkie_cve-2021-27850
Vulnerability from fkie_nvd
Published
2021-04-15 08:15
Modified
2024-11-21 05:58
Severity ?
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
▼ | URL | Tags | |
---|---|---|---|
security@apache.org | http://www.openwall.com/lists/oss-security/2021/04/15/1 | Exploit, Mailing List, Third Party Advisory | |
security@apache.org | https://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3E | Mailing List, Vendor Advisory | |
security@apache.org | https://security.netapp.com/advisory/ntap-20210528-0002/ | Third Party Advisory | |
af854a3a-2127-422b-91ae-364da2661108 | http://www.openwall.com/lists/oss-security/2021/04/15/1 | Exploit, Mailing List, Third Party Advisory | |
af854a3a-2127-422b-91ae-364da2661108 | https://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3E | Mailing List, Vendor Advisory | |
af854a3a-2127-422b-91ae-364da2661108 | https://security.netapp.com/advisory/ntap-20210528-0002/ | Third Party Advisory |
{ "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": [ "Mailing List", "Vendor Advisory" ], "url": "https://lists.apache.org/thread.html/r237ff7f286bda31682c254550c1ebf92b0ec61329b32fbeb2d1c8751%40%3Cusers.tapestry.apache.org%3E" }, { "source": "security@apache.org", "tags": [ "Third Party Advisory" ], "url": "https://security.netapp.com/advisory/ntap-20210528-0002/" }, { "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": [ "Exploit", "Mailing List", "Third Party Advisory" ], "url": "http://www.openwall.com/lists/oss-security/2021/04/15/1" }, { "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": [ "Mailing List", "Vendor Advisory" ], "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/" } ], "sourceIdentifier": "security@apache.org", "vulnStatus": "Modified", "weaknesses": [ { "description": [ { "lang": "en", "value": "CWE-200" }, { "lang": "en", "value": "CWE-502" } ], "source": "security@apache.org", "type": "Secondary" }, { "description": [ { "lang": "en", "value": "CWE-502" } ], "source": "nvd@nist.gov", "type": "Primary" } ] }
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Sightings
Author | Source | Type | Date |
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Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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