CVE-2017-3863 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 CSCut50727.
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Analysis
by VulDB Data Team • 12/21/2020
The vulnerability identified as CVE-2017-3863 represents a critical security flaw within the EnergyWise module of Cisco IOS and IOS XE software versions spanning from 12.2 through 15.6 and 3.2 through 3.18 respectively. This vulnerability falls under the category of improper input validation and buffer handling, specifically manifesting as a buffer overflow condition that can be exploited remotely without authentication. The EnergyWise module is designed to facilitate IPv4 communication for network energy management purposes, making it a legitimate component within enterprise networking infrastructure. The flaw resides in the packet parsing mechanism that processes EnergyWise packets destined for devices configured as EnergyWise domain members, creating an attack surface that can be leveraged by malicious actors to disrupt network operations.
The technical implementation of this vulnerability stems from inadequate bounds checking within the EnergyWise packet processing logic. When an attacker sends specially crafted EnergyWise packets to a vulnerable device, the system fails to properly validate the packet contents before attempting to process them within allocated memory buffers. This failure to validate input data creates a condition where maliciously constructed packets can exceed the allocated buffer space, resulting in memory corruption and subsequent system instability. The vulnerability specifically affects IPv4 packets, as the implementation does not properly handle the packet structure and data fields that are unique to IPv4 communication protocols. The attack vector requires no authentication credentials and can be executed from remote locations, making it particularly dangerous in network environments where such devices are exposed to untrusted network traffic.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the reliability and availability of critical network infrastructure. When exploited successfully, the vulnerability can cause the affected device to reload automatically, creating a denial of service condition that affects network connectivity and services dependent on that specific device. This reload behavior can occur repeatedly if the attacker maintains the attack, leading to sustained disruption of network operations and potential cascading failures within the network topology. The vulnerability affects devices configured as EnergyWise domain members, which are typically found in enterprise environments where network energy management is implemented, making the impact more significant in large-scale deployments. Network administrators may experience service degradation or complete outages depending on the role and importance of the affected device within the network architecture.
Mitigation strategies for CVE-2017-3863 should focus on immediate patch deployment and network segmentation approaches to limit exposure. Cisco has released software updates addressing this vulnerability, and organizations should prioritize applying these patches to all affected devices as soon as possible. Network segmentation represents an effective interim measure where EnergyWise traffic can be restricted to trusted network segments, reducing the attack surface available to potential attackers. Implementing access control lists and firewall rules to filter EnergyWise traffic can also provide additional protection, particularly when the EnergyWise functionality is not actively required for network operations. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and maps to ATT&CK technique T1499.002 for network denial of service attacks. Organizations should also consider monitoring network traffic for unusual EnergyWise packet patterns that might indicate exploitation attempts, as these attacks typically involve sending malformed packets to trigger the buffer overflow condition.