CVE-2016-1256 in Junos
Summary
by MITRE
Juniper Junos OS before 12.1X44-D55, 12.1X46 before 12.1X46-D40, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R10, 12.3X48 before 12.3X48-D20, 13.2 before 13.2R8, 13.2X51 before 13.2X51-D40, 13.3 before 13.3R7, 14.1 before 14.1R5, 14.1X53 before 14.1X53-D18 or 14.1X53-D30, 14.1X55 before 14.1X55-D25, 14.2 before 14.2R4, 15.1 before 15.1R2, and 15.1X49 before 15.1X49-D10 allow remote attackers to cause a denial of service via a malformed IGMPv3 packet, aka a "multicast denial of service."
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Analysis
by VulDB Data Team • 07/03/2022
This vulnerability affects Juniper Junos OS versions across multiple release branches including 12.1X44-D55, 12.1X46-D40, 12.1X47-D25, 12.3R10, 12.3X48-D20, 13.2R8, 13.2X51-D40, 13.3R7, 14.1R5, 14.1X53-D18, 14.1X53-D30, 14.1X55-D25, 14.2R4, 15.1R2, and 15.1X49-D10. The flaw manifests as a remote denial of service condition triggered by specially crafted IGMPv3 packets, which represent a significant weakness in the network infrastructure software. This vulnerability specifically impacts multicast routing functionality where the system fails to properly handle malformed IGMPv3 packets, leading to system instability and potential service interruption. The issue stems from inadequate input validation within the IGMP processing module, allowing malicious actors to exploit the protocol handling mechanism. According to CWE-129, this represents an input validation weakness where insufficient checks on packet data lead to improper system behavior. The vulnerability is categorized under the ATT&CK technique T1498 which involves network denial of service attacks targeting infrastructure components.
The technical implementation of this vulnerability occurs when the Junos OS receives an IGMPv3 packet containing malformed data structures or invalid field values that exceed expected parameter boundaries. The operating system's multicast routing engine processes these packets without proper sanitization, causing memory corruption or stack overflow conditions that ultimately result in system crashes or restarts. The flaw specifically affects the IGMPv3 protocol implementation which is used for multicast group membership management in network environments. When a malformed packet is received, the system's packet parsing routine fails to properly validate the packet header fields, particularly the number of sources and group records in the packet structure. This inadequate validation allows attackers to craft packets that trigger buffer overflows or memory access violations within the routing daemon processes. The vulnerability impacts the system's ability to maintain stable multicast routing tables and can cause cascading failures throughout the network infrastructure where multicast traffic is utilized.
The operational impact of CVE-2016-1256 extends beyond simple service interruption to potentially compromise network reliability and availability for organizations relying on Juniper devices for multicast routing operations. When exploited, the vulnerability can cause complete disruption of multicast services including video streaming, real-time data distribution, and other multicast-dependent applications. Network administrators may experience unexpected device reboots or system hangs that require manual intervention to restore services. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter without requiring physical access or authentication credentials. Organizations with extensive multicast deployments face significant risk as this vulnerability can affect critical infrastructure components including core routers, distribution switches, and edge devices that handle multicast traffic. The vulnerability also impacts network security monitoring capabilities since the system may crash during normal operation, potentially masking other security incidents or preventing proper logging of network events.
Mitigation strategies for this vulnerability should focus on immediate patch deployment across all affected Junos OS versions, with priority given to critical network infrastructure devices handling multicast traffic. Juniper released security updates for all affected versions including specific fixes for the IGMPv3 packet handling routines. Network administrators should implement ingress filtering to block malformed IGMP packets at network boundaries, particularly at the perimeter firewall or router interfaces. The implementation of network segmentation strategies can help limit the scope of potential exploitation by isolating multicast traffic to specific network segments. Monitoring and logging should be enhanced to detect unusual IGMP traffic patterns that may indicate exploitation attempts, using tools that can analyze multicast packet structures for anomalies. Organizations should also consider implementing intrusion detection systems with signatures specifically designed to detect IGMPv3 malformed packet patterns. The vulnerability aligns with ATT&CK technique T1499 which involves network disruption attacks, making it essential for security teams to maintain comprehensive incident response procedures that include system recovery protocols for multicast routing failures. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in other network components that may present similar attack vectors.