Apache Solr velocity Remote Code Execution Vulnerability Handling Guide

Apache Solr velocity Remote Code Execution Vulnerability Handling Guide

novembro 12, 2019 | Adeline Zhang

Vulnerability Description

On October 30, @_S00pY disclosed the exploitation of Apache Solr Remote Code Execution Vulnerability, which allows attackers to implement remote code execution via velocity templates. After testing, the vulnerability can be successfully triggered, and no official security patch has been released.

This vulnerability needs to be triggered in two steps. First, the attacker needs to modify the “params.Resource.Loader.Enabled” configuration item to True through the config API, and then complete the vulnerability trigger by sending a malicious velocity template.

Some POC codes are as follows:

After successful utilization, arbitrary commands can be executed on the server.

Scope of Impact

Affected Versions

  • Apache Solr <= 8.2.0 (versions with config API may be affected by this vulnerability)

Vulnerability Detection

  • Manual Test

If any of the following conditions are met, the current system may be affected by this vulnerability.

  1. Access http:/ /hostname /Solr/nstance name /config and find that the config API is open.
  2. A configfollay.json file exists in the instance configuration directory, under which the configuration item “params.Resource.Loader.Enabled”:”true” can be found. By default, there is no configfollay.json file.

  1. In the global configuration file solrconfig.xml, the configuration item “params.resource.loader.enabled” is “true”.

Vulnerability Mitigation

  • Product Protection

Users deployed with NIPS can protect against this vulnerability by using protection rule 23982.

  • Workaround
  1. Users can disable access to / Solr / instance name / config by access control.
  2. If ” params.resource.loader.enabled:”true” exists in the configloverlay.json configuration file, change “true” to “false”.

  1. If the following configuration <bool name=”params.resource.loader.enabled”>true</bool> exists in the velocityresponsewriter in the solrconfig.xml configuration file, modify it to “false”.

  1. Add security authentication. For detailed configuration methods, please refer to the document released by Apache:



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