CVE-2024-28732 in Ryu
Summary
by MITRE • 04/08/2024
An issue was discovered in OFPMatch in parser.py in Faucet SDN Ryu version 4.34, allows remote attackers to cause a denial of service (DoS) (infinite loop).
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Analysis
by VulDB Data Team • 08/22/2024
The vulnerability identified as CVE-2024-28732 represents a critical denial of service flaw within the Faucet SDN Ryu framework version 4.34. This issue specifically affects the OFPMatch component in the parser.py module, which serves as a fundamental parsing mechanism for OpenFlow protocol messages within the SDN controller environment. The flaw manifests when remote attackers exploit malformed or specially crafted OpenFlow messages that trigger an infinite loop within the parsing logic, effectively causing the controller to become unresponsive and unable to process legitimate network traffic.
The technical root cause of this vulnerability lies in insufficient input validation and error handling within the OFPMatch parsing functionality. When the parser encounters malformed OpenFlow match fields or unexpected message structures, the control flow within parser.py does not properly terminate execution, instead falling into an infinite loop that consumes CPU resources and prevents the system from processing subsequent network events. This behavior aligns with CWE-835, which specifically addresses infinite loops in software implementations where the loop termination condition is not properly validated or handled. The vulnerability demonstrates a classic example of how improper state management and lack of input sanitization can create exploitable conditions that compromise system availability.
From an operational perspective, this vulnerability presents a significant risk to network infrastructure that relies on Faucet SDN Ryu controllers for traffic management and policy enforcement. An attacker who can successfully exploit this DoS condition can effectively disrupt network operations by causing the controller to become unresponsive, leading to complete loss of network control and potential service degradation. The impact extends beyond simple disruption as it can affect the entire SDN ecosystem, potentially causing cascading failures in network services that depend on the controller for proper operation. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter, making it particularly dangerous for publicly accessible SDN controllers.
The exploitation of CVE-2024-28732 aligns with tactics described in the MITRE ATT&CK framework under the T1499 category for network denial of service attacks, where attackers specifically target network infrastructure to disrupt service availability. Organizations using Faucet SDN Ryu version 4.34 should immediately implement mitigations including input validation measures, rate limiting for OpenFlow messages, and monitoring for unusual CPU consumption patterns that may indicate exploitation attempts. The most effective long-term solution involves upgrading to a patched version of the Faucet SDN Ryu framework where proper input validation and loop termination conditions have been implemented to prevent the infinite loop scenario. Network administrators should also consider implementing redundant controller systems and automated failover mechanisms to minimize the impact of such DoS attacks on overall network operations and ensure continued service availability during potential exploitation attempts.