title: graylog2-server vulnerable to instantiation of arbitrary classes triggered by API request
description: Graylog is a free and open log management platform. Starting in version 2.0.0 and prior to versions 5.1.11 and 5.2.4, arbitrary classes can be loaded and instantiated using a HTTP PUT request to the `/api/system/cluster_config/` endpoint. Graylog's cluster config system uses fully qualified class names as config keys. To validate the existence of the requested class before using them, Graylog loads the class using the class loader. If a user with the appropriate permissions performs the request, arbitrary classes with 1-arg String constructors can be instantiated. This will execute arbitrary code that is run during class instantiation. In the specific use case of `java.io.File`, the behavior of the internal web-server stack will lead to information exposure by including the entire file content in the response to the REST request. Versions 5.1.11 and 5.2.4 contain a fix for this issue.
problem types: CWE-284: Improper Access Control
affected:
{
vendor: Graylog2
product: graylog2-server
versions:
version: >= 2.0.0, < 5.1.11, status: affected
version: >= 5.2.0, < 5.2.4, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
version: 3.1
]