Horizon Alert
Summary of the vulnerability and why it matters
This vulnerability impacts Apache Tomcat, a widely used web server technology. It allows bypassing security restrictions due to improper handling of web addresses, potentially enabling unauthorized access to applications hosted on Tomcat. The main concern is confirming relevance and exposure to our environment.
- Web addresses can be manipulated to bypass security.
- Affects systems hosting public-facing applications.
- Assess if our Tomcat instances are exposed.
Attack Path
How an attacker could exploit the issue
An attacker can exploit this vulnerability by sending specially crafted requests to a vulnerable Apache Tomcat server. The server's rewrite valve, which processes URLs, incorrectly handles hex-encoded characters in URLs. This misinterpretation can allow an attacker to bypass configured security constraints, potentially leading to unauthorized access or other unintended actions.
- No authentication or privileges needed.
- Malicious URL request to rewrite valve.
- Bypasses security constraints.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability could allow unauthorized access to restricted resources on systems running vulnerable Apache Tomcat versions when specific URL encoding configurations are used. When improperly handled, hexadecimal-encoded characters in URLs might bypass security constraints, potentially exposing sensitive information or allowing unauthorized actions.
- System access to restricted resources.
- Bypass of security constraints via URL encoding.
- Unauthorized access to application data.
Operational Fix
Recommended remediation, mitigation, and detection steps
Security and infrastructure teams are most likely responsible for addressing this critical vulnerability in Apache Tomcat, especially since it's exposed to public internet traffic via the rewrite valve. The immediate first step is to identify all instances of affected Tomcat versions, determine their reachability and business criticality, and then confirm the accountable owner for remediation planning.
- Infrastructure and security teams own this.
- Verify affected Tomcat instances and exposure.
- Plan risk-based remediation and vendor coordination.
