Horizon Alert
Summary of the vulnerability and why it matters
The Apache Solr search platform is susceptible to a flaw within its VelocityResponseWriter. This vulnerability allows for remote code execution if specific conditions are met, potentially impacting the confidentiality, integrity, and availability of systems. The flaw arises from the ability to process Velocity templates, which could be user-defined or provided through configuration.
- Vulnerable Apache Solr component
- Allows remote code execution
- Business risk to systems and data
Attack Path
How an attacker could exploit the issue
The identified vulnerability in Apache Solr allows for remote code execution through the VelocityResponseWriter. An attacker can leverage this by providing a malicious Velocity template, which, when rendered, can lead to unauthorized control over the affected system. This attack path requires specific configuration or administrative access to enable the template rendering functionality.
- Exposure via network access.
- Attacker provides a malicious template.
- Attacker gains system control.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability in Apache Solr allows for remote code execution. It can be exploited by an attacker with limited access to the affected system. The potential impact includes unauthorized code execution, which could lead to a compromise of the system and sensitive data.
- Likely attacker skill level: Moderate.
- Required access or conditions: Some administrative configuration access.
- Business risk or urgency: High.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
An organization should prioritize identifying and securing its Apache Solr instances vulnerable to remote code execution. This vulnerability arises from the VelocityResponseWriter's handling of Velocity templates, which attackers could exploit to execute arbitrary code on affected systems. The risk is heightened for configurations where custom response writers are defined with specific settings that enable parameter-based template loading, or where un-trusted configsets are deployed.
- Locate all exposed Solr assets.
- Restrict network access to Solr.
- Apply vendor updates and confirm fixes.
- Monitor for suspicious activity.
