CVE-2017-3862 in IOS
Summary
by MITRE
Multiple vulnerabilities in the EnergyWise module of Cisco IOS (12.2 and 15.0 through 15.6) and Cisco IOS XE (3.2 through 3.18) could allow an unauthenticated, remote attacker to cause a buffer overflow condition or a reload of an affected device, leading to a denial of service (DoS) condition. These vulnerabilities are due to improper parsing of crafted EnergyWise packets destined to an affected device. An attacker could exploit these vulnerabilities by sending crafted EnergyWise packets to be processed by an affected device. An exploit could allow the attacker to cause a buffer overflow condition or a reload of the affected device, leading to a DoS condition. Cisco IOS Software and Cisco IOS XE Software support EnergyWise for IPv4 communication. Only IPv4 packets destined to a device configured as an EnergyWise domain member can trigger these vulnerabilities. IPv6 packets cannot be used to trigger these vulnerabilities. Cisco Bug ID CSCuu76493.
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Analysis
by VulDB Data Team • 12/21/2020
The vulnerability described in CVE-2017-3862 represents a critical security flaw within the EnergyWise module of Cisco's IOS and IOS XE operating systems. This issue affects versions 12.2 and 15.0 through 15.6 of Cisco IOS, along with versions 3.2 through 3.18 of Cisco IOS XE software. The EnergyWise module is designed to facilitate energy management communications within networked devices, particularly supporting IPv4 communication for networked energy management systems. The vulnerability stems from inadequate input validation and buffer handling within the EnergyWise packet processing logic, creating a pathway for remote exploitation without requiring authentication credentials.
The technical flaw manifests as improper parsing of specially crafted EnergyWise packets that are destined for devices configured as EnergyWise domain members. When these malformed packets are received and processed by an affected device, they trigger buffer overflow conditions or force the device to reload its operating system. This buffer overflow vulnerability specifically aligns with CWE-121, which addresses stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The vulnerability is particularly concerning because it operates at the network layer where EnergyWise packets are processed, allowing an attacker to manipulate the device's memory allocation and execution flow through carefully constructed packet payloads.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it can result in complete service disruption for networked devices that rely on EnergyWise functionality. Network administrators may experience unexpected device reboots, leading to temporary loss of energy management capabilities across affected networks. The DoS condition can be particularly disruptive in enterprise environments where EnergyWise is used for network-wide power management and monitoring. Attackers can exploit this vulnerability remotely without authentication, making it especially dangerous as it requires no insider knowledge or physical access to the target devices. The vulnerability specifically affects IPv4 packets, with IPv6 communications being immune to this particular attack vector, which suggests the issue is tied to the specific IPv4 processing code within the EnergyWise module.
The attack vector for this vulnerability follows the ATT&CK framework's technique T1210, which involves exploitation of remote services through manipulation of input data. An attacker needs only to send specially crafted EnergyWise packets to an affected device to trigger the vulnerability, making it highly accessible for automated exploitation. The vulnerability's classification as a remote code execution risk, while limited to DoS conditions, still represents a significant threat to network availability and stability. Organizations implementing EnergyWise functionality across their network infrastructure face particular risk, as the vulnerability can be exploited by anyone who can send packets to the affected device's EnergyWise listening ports. Cisco's identification of this issue through Bug ID CSCuu76493 indicates the company recognized the severity of the buffer overflow conditions that can be triggered by malformed EnergyWise packet processing.
Mitigation strategies for this vulnerability should prioritize immediate software updates to the latest available IOS and IOS XE releases that contain patches addressing the EnergyWise parsing issues. Network segmentation and access control measures can help limit exposure by restricting which devices can receive EnergyWise packets, though this approach may impact legitimate EnergyWise functionality. Implementing network monitoring to detect unusual EnergyWise packet patterns or traffic spikes can help identify potential exploitation attempts. Organizations should also consider disabling EnergyWise functionality on affected devices if the feature is not critical to their operations, as this provides a complete defense against the vulnerability. The patching process should include thorough testing in non-production environments to ensure that updates do not introduce compatibility issues with existing EnergyWise deployments, particularly in large enterprise networks where EnergyWise may be integrated with complex power management systems and building automation protocols.