CVE-2016-2342 in Quagga
Summary
by MITRE
The bgp_nlri_parse_vpnv4 function in bgp_mplsvpn.c in the VPNv4 NLRI parser in bgpd in Quagga before 1.0.20160309, when a certain VPNv4 configuration is used, relies on a Labeled-VPN SAFI routes-data length field during a data copy, which allows remote attackers to execute arbitrary code or cause a denial of service (stack-based buffer overflow) via a crafted packet.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability identified as CVE-2016-2342 represents a critical stack-based buffer overflow in the BGP VPNv4 NLRI parsing functionality of Quagga routing software. This flaw exists within the bgp_nlri_parse_vpnv4 function located in bgp_mplsvpn.c, specifically affecting Quagga versions prior to 1.0.20160309. The vulnerability arises from improper validation of the Labeled-VPN SAFI routes-data length field during packet processing, creating a scenario where maliciously crafted BGP packets can trigger unintended memory access patterns. The issue is particularly dangerous because it can be exploited remotely by attackers who send specially constructed VPNv4 NLRI packets to vulnerable Quagga instances, potentially leading to arbitrary code execution or complete system compromise.
The technical exploitation of this vulnerability stems from the function's reliance on an unvalidated length field from the incoming packet data to determine how much memory to copy during the parsing process. When a malicious actor crafts a packet with an oversized length value in the Labeled-VPN SAFI routes-data field, the function performs a memory copy operation that exceeds the allocated buffer boundaries. This classic buffer overflow condition allows attackers to overwrite adjacent memory locations, potentially corrupting program execution flow and enabling arbitrary code execution. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which is a well-documented weakness in software systems where insufficient bounds checking allows memory corruption.
The operational impact of CVE-2016-2342 extends beyond simple denial of service to encompass full system compromise capabilities. Network infrastructure devices running vulnerable Quagga versions become potential attack vectors for adversaries seeking to gain unauthorized access to routing systems, which are critical components of network infrastructure. The vulnerability affects BGP implementations that utilize VPNv4 configuration settings, making it particularly concerning for service providers and enterprise networks that rely on MPLS VPN services. According to ATT&CK framework, this vulnerability maps to T1059.007 for remote code execution and T1499.004 for network denial of service, representing significant threats to network availability and integrity. Organizations using affected Quagga versions face risks of data exfiltration, network disruption, and potential lateral movement within their network infrastructure.
Mitigation strategies for CVE-2016-2342 primarily involve immediate patching of Quagga software to version 1.0.20160309 or later, which includes proper bounds checking for the VPNv4 NLRI parsing routine. Network administrators should also implement packet filtering rules to restrict BGP traffic from untrusted sources and consider enabling BGP route validation mechanisms. Additionally, monitoring systems should be configured to detect anomalous BGP packet patterns that might indicate exploitation attempts. Organizations should conduct comprehensive vulnerability assessments of their routing infrastructure and implement network segmentation to limit the potential impact of successful exploitation. The fix implemented in Quagga addresses the core issue by introducing proper validation of the length field before any memory copy operations occur, preventing the buffer overflow condition from being triggered.