CVE-2017-7509 in Certificate Server
Summary
by MITRE
An input validation error was found in Red Hat Certificate System s handling of client provided certificates before 8.1.20-1. If the certreq field is not present in a certificate an assertion error is triggered causing a denial of service.
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Analysis
by VulDB Data Team • 11/10/2024
The vulnerability identified as CVE-2017-7509 represents a critical input validation flaw within Red Hat Certificate System versions prior to 8.1.20-1. This issue stems from inadequate handling of client-provided certificate requests where the system fails to properly validate the presence of required fields in certificate requests. The flaw manifests when the certreq field is absent from incoming certificate requests, triggering an assertion error that leads to system termination. This vulnerability operates at the application layer and specifically impacts the certificate management infrastructure, making it particularly dangerous for organizations relying on certificate-based authentication systems.
The technical implementation of this vulnerability demonstrates a classic lack of proper input validation and error handling mechanisms. When a client submits a certificate request without the mandatory certreq field, the Red Hat Certificate System's internal validation logic encounters an unexpected condition that causes an assertion failure. This assertion error is not gracefully handled but instead results in an immediate system crash or denial of service condition. The vulnerability maps to CWE-20, which describes improper input validation, and CWE-704, which covers incorrect type conversion or cast. The system's failure to anticipate and handle missing mandatory fields represents a fundamental flaw in defensive programming practices.
From an operational perspective, this vulnerability creates significant risk for certificate management systems that depend on Red Hat Certificate System. An attacker could exploit this weakness to perform denial of service attacks against certificate authorities, effectively preventing legitimate certificate issuance and renewal operations. The impact extends beyond simple service disruption as certificate authorities are critical infrastructure components that enable secure communications across networks, applications, and services. Organizations using affected versions could experience complete certificate service outages, potentially affecting thousands of systems that rely on certificate-based authentication and encryption. This vulnerability aligns with ATT&CK technique T1499.004, which describes denial of service via resource exhaustion or system interruption.
The mitigation strategy for CVE-2017-7509 involves immediate upgrade to Red Hat Certificate System version 8.1.20-1 or later, which includes proper input validation and error handling for certificate requests. Organizations should also implement monitoring solutions to detect anomalous certificate request patterns that might indicate attempted exploitation. Network segmentation and access controls should be reinforced around certificate authority systems to limit exposure. Additionally, implementing proper logging and alerting mechanisms can help detect when assertion errors occur, providing early warning of potential exploitation attempts. The fix addresses the root cause by implementing robust input validation that checks for the presence of required fields before proceeding with certificate processing, thereby preventing the assertion failure that leads to denial of service conditions.