CVE-2019-12110 in MiniUPnPd
Summary
by MITRE
An AddPortMapping Denial Of Service vulnerability in MiniUPnP MiniUPnPd through 2.1 exists due to a NULL pointer dereference in upnpredirect.c.
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Analysis
by VulDB Data Team • 09/21/2023
The CVE-2019-12110 vulnerability represents a critical denial of service weakness in MiniUPnP MiniUPnPd versions up to 2.1, specifically within the AddPortMapping functionality. This vulnerability stems from a NULL pointer dereference condition in the upnpredirect.c source file, which fundamentally compromises the device's ability to process port mapping requests. The issue manifests when the system attempts to handle incoming port mapping commands without proper validation of pointer references, creating an exploitable condition that can be leveraged by malicious actors to disrupt network services.
The technical flaw occurs during the processing of UPnP port mapping operations where the software fails to adequately validate input parameters before attempting to dereference pointers. This NULL pointer dereference vulnerability falls under the CWE-476 category, specifically addressing NULL pointer dereference conditions that can lead to system crashes or service interruptions. The vulnerability exists because the upnpredirect.c module does not perform proper null checks on dynamically allocated memory pointers before accessing them, allowing attackers to craft specially formatted port mapping requests that trigger the dereference of uninitialized or freed memory locations.
From an operational impact perspective, this vulnerability enables attackers to execute remote denial of service attacks against devices running affected MiniUPnPd versions. The consequence is a complete disruption of UPnP services, rendering the device incapable of processing legitimate port mapping requests from authorized network clients. Network administrators may experience complete loss of connectivity for services that depend on UPnP port forwarding, including home automation systems, gaming consoles, and remote access applications. The attack vector requires minimal privileges and can be executed remotely, making it particularly dangerous for devices exposed to untrusted networks.
The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks targeting network infrastructure components. Organizations utilizing affected devices may face significant operational disruption as the service becomes unavailable, potentially affecting business continuity and user access to network services. The impact extends beyond simple service interruption to encompass potential security implications, as the device's inability to properly handle port mapping requests may leave network configurations in inconsistent states.
Mitigation strategies should focus on immediate patching of affected systems to version 2.2 or later, which includes the necessary pointer validation fixes. Network segmentation and access controls should be implemented to limit exposure of affected devices to untrusted networks, while monitoring systems should be deployed to detect anomalous UPnP traffic patterns. Additionally, administrators should consider disabling UPnP functionality entirely if port mapping services are not required, as this eliminates the attack surface entirely. Regular vulnerability assessments and network scanning should be conducted to identify other potentially affected systems, particularly in enterprise environments where multiple devices may be running outdated MiniUPnPd versions.