CVE-2018-0346 in SD-WAN Solution
Summary
by MITRE
A vulnerability in the Zero Touch Provisioning service of the Cisco SD-WAN Solution could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect bounds checks for certain values in packets that are sent to the Zero Touch Provisioning service of the affected software. An attacker could exploit this vulnerability by sending malicious packets to the affected software for processing. When the software processes the packets, a buffer overflow condition could occur and cause an affected device to reload. A successful exploit could allow the attacker to cause a temporary DoS condition while the device reloads. This vulnerability can be exploited only by traffic that is destined for an affected device. It cannot be exploited by traffic that is transiting a device. This vulnerability affects the following Cisco products if they are running a release of the Cisco SD-WAN Solution prior to Release 18.3.0: vBond Orchestrator Software, vManage Network Management Software, vSmart Controller Software. Cisco Bug IDs: CSCvi69914.
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Analysis
by VulDB Data Team • 03/08/2020
The vulnerability identified as CVE-2018-0346 resides within the Zero Touch Provisioning service of Cisco's SD-WAN Solution, representing a critical security flaw that enables unauthenticated remote attackers to induce denial of service conditions on targeted devices. This vulnerability specifically impacts the vBond Orchestrator Software, vManage Network Management Software, and vSmart Controller Software components, affecting all Cisco SD-WAN Solution releases prior to version 18.3.0. The flaw manifests through inadequate bounds checking mechanisms within the packet processing logic of the Zero Touch Provisioning service, creating a pathway for malicious actors to exploit the system through carefully crafted network traffic.
The technical exploitation of this vulnerability occurs when an attacker sends specially formatted packets to the affected service, which then processes these packets without proper validation of input parameters. The insufficient bounds checking leads to a buffer overflow condition that ultimately forces the affected device to undergo a complete reload cycle. This buffer overflow vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and more specifically aligns with CWE-129, addressing improper validation of array indices. The attack vector requires that the malicious traffic be directed specifically toward the vulnerable device rather than passing through it, limiting the scope to targeted attacks against specific endpoints rather than network-wide exploitation.
The operational impact of this vulnerability extends beyond simple service disruption, as it creates a temporary denial of service condition that can significantly impact network operations and management capabilities. When the affected device reloads due to the buffer overflow, it temporarily removes itself from the network management infrastructure, potentially disrupting network connectivity and configuration management processes. This disruption can be particularly problematic in enterprise environments where continuous network availability is critical for business operations. The vulnerability's exploitation requires no authentication credentials, making it accessible to any attacker with network access to the targeted device, which aligns with ATT&CK technique T1499.002 for network denial of service attacks.
Cisco has documented this vulnerability with bug ID CSCvi69914 and has released patches for the 18.3.0 software release to address the bounds checking deficiencies. Organizations should implement immediate mitigation strategies including network segmentation to limit direct access to vulnerable devices, firewall rules to restrict traffic to the Zero Touch Provisioning service ports, and network monitoring to detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and bounds checking in network services, particularly those that process untrusted network traffic. Regular security updates and patch management processes become critical in preventing exploitation of similar vulnerabilities, as this flaw could have been prevented through proper software development practices and thorough security testing of network service components. Organizations should also consider implementing intrusion detection systems to monitor for suspicious packet patterns that may indicate exploitation attempts against this specific vulnerability.