CVE-2015-0650 in IOS
Summary
by MITRE
The Service Discovery Gateway (aka mDNS Gateway) in Cisco IOS 12.2, 12.4, 15.0, 15.1, 15.2, 15.3, and 15.4 and IOS XE 3.9.xS and 3.10.xS before 3.10.4S, 3.11.xS before 3.11.3S, 3.12.xS before 3.12.2S, and 3.13.xS before 3.13.1S allows remote attackers to cause a denial of service (device reload) by sending malformed mDNS UDP packets over (1) IPv4 or (2) IPv6, aka Bug ID CSCup70579.
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability identified as CVE-2015-0650 represents a critical denial of service flaw within Cisco IOS and IOS XE operating systems that affects multiple software versions across different release branches. This vulnerability specifically targets the Service Discovery Gateway component, also known as the mDNS Gateway, which is responsible for handling multicast domain name system queries and responses. The mDNS protocol operates over both IPv4 and IPv6 networks and is commonly used for local network service discovery, making this vulnerability particularly concerning as it can be exploited from remote locations without requiring authentication or privileged access. The flaw manifests when the system receives malformed mDNS UDP packets, which are crafted to trigger unexpected behavior in the packet processing logic, ultimately leading to device instability and complete system reload.
The technical implementation of this vulnerability resides in the insufficient input validation and error handling mechanisms within the mDNS gateway processing code. When the system receives malformed UDP packets containing invalid mDNS headers, resource structures, or malformed data payloads, the parsing routines fail to properly validate the incoming data before attempting to process it. This lack of proper bounds checking and data sanitization creates a condition where the system's memory management routines become corrupted or the execution flow is disrupted, causing the device to crash and subsequently reload its operating system. The vulnerability affects the core network infrastructure components that rely on mDNS for service discovery, including routers, switches, and other network devices running the affected software versions, making it a widespread concern across enterprise and service provider networks.
The operational impact of this vulnerability extends beyond simple network disruption, as it can be exploited by remote attackers to cause widespread service degradation across multiple network segments. Attackers can leverage this vulnerability by simply sending crafted UDP packets to the affected device, requiring no special credentials or network access privileges. The device reload caused by this vulnerability results in temporary loss of network connectivity for all services relying on the affected device, potentially causing cascading failures in network infrastructure. Network administrators may experience significant downtime as devices restart and re-establish their network connections, while the repeated exploitation can lead to sustained service disruption that affects business operations and network availability. The vulnerability particularly impacts service discovery mechanisms that depend on mDNS for local network service resolution, including printer discovery, file sharing, and other local network services that rely on multicast DNS queries.
Mitigation strategies for this vulnerability involve implementing immediate software updates and patches provided by Cisco to address the specific mDNS processing flaws. Organizations should prioritize patching all affected devices running the vulnerable IOS and IOS XE versions, particularly those that are exposed to untrusted network segments or external traffic. Network segmentation and access control measures should be implemented to limit exposure of affected devices to external networks, while monitoring systems should be configured to detect unusual mDNS traffic patterns that might indicate exploitation attempts. Cisco recommends disabling mDNS functionality on affected devices when possible, though this may impact legitimate service discovery operations. The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and represents a classic example of how insufficient input validation can lead to denial of service conditions. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network disruption through service exhaustion and the T1566.001 technique for initial access through network-based attacks, making it a significant concern for organizations implementing comprehensive cybersecurity defense strategies.