Horizon Alert
Summary of the vulnerability and why it matters
A buffer under-read vulnerability in Apache Tomcat could lead to response data being split between requests, potentially causing the second request to fail and data from the first request to leak. This affects internet-facing web servers and servlet containers that handle user traffic.
- Data leakage and request failures are possible.
- Widely used web server technology is affected.
- Confirm relevance and exposure for business systems.
Attack Path
How an attacker could exploit the issue
An attacker could exploit a buffer under-read vulnerability in Apache Tomcat by sending a specially crafted, large non-blocking write request. This could cause the response body to be incorrectly split between consecutive requests on the same connection, potentially leading to the failure of the second request and data leakage from the first.
- Exposed to network, no authentication required.
- Large non-blocking write request.
- Request failure and potential data leakage.
Live Threat
Current exploitation, exposure, and threat context
A buffer under-read vulnerability in Apache Tomcat could lead to the response body being split between requests. This might cause the second request to fail and potentially leak data from the first response to the second when a large non-blocking write occurs on a shared connection.
- Response data from previous requests.
- Data may leak between requests.
- Service instability and data exposure.
Operational Fix
Recommended remediation, mitigation, and detection steps
Real-World Ownership
This critical vulnerability in Apache Tomcat, a widely deployed web server, likely impacts teams responsible for hosting web applications or services. The first practical step is to inventory all Tomcat instances, assess their external reachability and business criticality, identify the accountable application or infrastructure owner, and then prioritize remediation efforts based on this risk assessment.
- Application or Infrastructure Owners
- Verify Tomcat instance reachability and criticality.
- Plan coordinated upgrade or mitigation.
