CVE-2015-4324 in NX-OS
Summary
by MITRE
Buffer overflow in Cisco NX-OS on Nexus 1000V devices for VMware vSphere 7.3(0)ZN(0.81), Nexus 3000 devices 7.3(0)ZN(0.81), Nexus 4000 devices 4.1(2)E1(1c), Nexus 7000 devices 7.2(0)N1(0.1), and Nexus 9000 devices 7.3(0)ZN(0.81) allows remote attackers to cause a denial of service (IGMP process restart) via a malformed IGMPv3 packet that is mishandled during memory allocation, aka Bug IDs CSCuv69713, CSCuv69717, CSCuv69723, CSCuv69732, and CSCuv48908.
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Analysis
by VulDB Data Team • 06/12/2022
The vulnerability identified as CVE-2015-4324 represents a critical buffer overflow condition affecting Cisco NX-OS software implementations across multiple Nexus device families including 1000V, 3000, 4000, 7000, and 9000 series switches. This flaw manifests specifically within the Internet Group Management Protocol version 3 (IGMPv3) processing functionality, where improperly constructed packets trigger memory allocation errors that ultimately result in service disruption. The vulnerability affects versions of NX-OS software that incorporate the specified release numbers, with particular emphasis on the 7.3(0)ZN(0.81) and 4.1(2)E1(1c) software versions across different device platforms. The issue stems from inadequate input validation and memory management within the IGMP processing module, creating an exploitable condition that can be leveraged remotely by malicious actors without requiring authentication credentials.
The technical implementation of this vulnerability involves a classic buffer overflow scenario where the NX-OS software fails to properly validate the size and structure of incoming IGMPv3 packets before processing them within memory allocation routines. When a malformed IGMPv3 packet is received, the system attempts to allocate memory buffers based on incorrect packet parameters, leading to memory corruption that causes the IGMP process to crash and restart. This process restart typically results in temporary network disruption as the system reinitializes the IGMP service, effectively creating a denial of service condition. The vulnerability is particularly concerning because it operates at the network protocol level, allowing attackers to exploit the flaw through standard network traffic without requiring physical access or elevated privileges, making it highly attractive to threat actors seeking to disrupt network operations.
The operational impact of this vulnerability extends beyond simple service disruption, potentially affecting network stability and availability across enterprise and data center environments that rely on Cisco Nexus switches for critical network infrastructure. Organizations utilizing affected device models may experience intermittent network outages or service degradation as the IGMP process repeatedly restarts, which can be particularly problematic in high-availability environments where continuous network operation is essential. The vulnerability affects both virtualized environments running Nexus 1000V devices on VMware vSphere platforms and physical hardware deployments across various Nexus series switches, indicating a widespread impact across Cisco's product portfolio. Network administrators may observe increased system logs indicating IGMP process restarts, which can complicate troubleshooting efforts and mask other potential security incidents.
Mitigation strategies for this vulnerability should focus on immediate software updates to address the root cause through official Cisco patches and updates. Organizations should prioritize applying the relevant security patches released by Cisco that specifically address the buffer overflow conditions in the IGMPv3 processing module. Network segmentation and access control measures can provide additional defense-in-depth layers by limiting exposure to potentially malicious traffic sources. Implementing network monitoring solutions that can detect unusual IGMP packet patterns or process restart events can help identify exploitation attempts before they cause significant disruption. Additionally, organizations should consider implementing temporary network filters or access control lists that restrict IGMP traffic from untrusted sources, though this approach must balance security benefits against potential impact on legitimate network operations. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and represents a typical example of how protocol processing flaws can be exploited for denial of service attacks, potentially mapping to ATT&CK technique T1499.002 for network denial of service operations.