CVE-2020-7217 in wicked
Summary
by MITRE
An ni_dhcp4_fsm_process_dhcp4_packet memory leak in openSUSE wicked 0.6.55 and earlier allows network attackers to cause a denial of service by sending DHCP4 packets with a different client-id.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/29/2024
The vulnerability identified as CVE-2020-7217 represents a critical memory leak flaw within the openSUSE wicked network management daemon version 0.6.55 and earlier. This issue specifically affects the ni_dhcp4_fsm_process_dhcp4_packet function which handles DHCPv4 packet processing within the wicked framework. The memory leak occurs when the daemon receives DHCP4 packets containing varying client-id values, creating a condition where allocated memory is not properly released back to the system. This flaw exists in the state machine implementation responsible for processing DHCPv4 communication flows, making it particularly dangerous in networked environments where DHCP services are actively utilized.
The technical exploitation of this vulnerability stems from the improper memory management within the DHCPv4 finite state machine component of wicked. When processing DHCP4 packets with different client-id values, the system fails to correctly deallocate memory resources that were previously allocated during packet processing operations. This memory leak accumulates over time as the daemon continues to receive and process DHCP packets, eventually leading to system resource exhaustion. The flaw is classified under CWE-401 as a failure to release memory resources, which directly impacts system stability and availability. The attacker need only send specially crafted DHCP4 packets with varying client-id values to trigger the memory leak condition, making this vulnerability particularly dangerous as it requires minimal effort to exploit.
The operational impact of CVE-2020-7217 extends beyond simple resource exhaustion to encompass complete service disruption and potential system instability. Network administrators managing systems running vulnerable versions of wicked may experience gradual degradation of network services as memory consumption increases, ultimately leading to denial of service conditions where the system becomes unresponsive to legitimate DHCP requests. This vulnerability can be particularly devastating in environments where continuous DHCP service availability is critical, such as enterprise networks, data centers, or network infrastructure devices that rely on wicked for network configuration management. The memory leak can affect not only the DHCP service itself but potentially impact other network services that depend on the system's memory resources, creating cascading failures within the network infrastructure.
Mitigation strategies for CVE-2020-7217 should prioritize immediate patching of affected systems to version 0.6.56 or later, which contains the necessary memory management fixes for the ni_dhcp4_fsm_process_dhcp4_packet function. Network administrators should implement monitoring solutions to track memory consumption patterns on systems running wicked, enabling early detection of potential exploitation attempts. Additionally, network segmentation and access control measures can help limit the impact of potential attacks by restricting unauthorized access to DHCP services. The vulnerability aligns with ATT&CK technique T1499.001 for resource exhaustion attacks, where adversaries exploit software flaws to consume system resources and cause denial of service conditions. Organizations should also consider implementing network intrusion detection systems that can identify unusual DHCP packet patterns and potential exploitation attempts, while maintaining regular security assessments to identify and remediate similar memory management vulnerabilities in network infrastructure components.