CVE-2018-0315 in IOS XE
Summary
by MITRE • 01/25/2023
A vulnerability in the authentication, authorization, and accounting (AAA) security services of Cisco IOS XE Software could allow an unauthenticated, remote attacker to execute arbitrary code on an affected device or cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect memory operations that the affected software performs when the software parses a username during login authentication. An attacker could exploit this vulnerability by attempting to authenticate to an affected device. A successful exploit could allow the attacker to execute arbitrary code on the affected device or cause the affected device to reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are running Cisco IOS XE Software Release Fuji 16.7.1 or Fuji 16.8.1 and are configured to use AAA for login authentication. Cisco Bug IDs: CSCvi25380.
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Analysis
by VulDB Data Team • 03/22/2023
The vulnerability described in CVE-2018-0315 represents a critical security flaw within Cisco IOS XE Software that specifically targets the authentication, authorization, and accounting (AAA) services. This weakness exists in the software's handling of username parsing during login authentication processes, creating an avenue for remote exploitation without requiring prior authentication credentials. The vulnerability affects devices running Cisco IOS XE Software Release Fuji 16.7.1 and Fuji 16.8.1, making it particularly concerning given the widespread deployment of these software versions across enterprise networks. The flaw manifests through improper memory operations that occur when the system processes user credentials during authentication attempts.
The technical exploitation of this vulnerability occurs when an attacker attempts to authenticate to an affected device, triggering the flawed memory handling mechanisms within the AAA service. This incorrect memory operation can lead to two primary outcomes: arbitrary code execution or unauthorized device reloads causing denial of service conditions. The memory corruption aspect of this vulnerability aligns with common software security weaknesses categorized under CWE-125 as "Out-of-bounds Read" or CWE-787 as "Out-of-bounds Write," where improper bounds checking leads to memory corruption that can be leveraged for privilege escalation. The vulnerability's remote nature means attackers can exploit it from outside the network perimeter, making it particularly dangerous for devices exposed to public internet access.
From an operational impact perspective, this vulnerability poses significant risks to network infrastructure security and availability. Network administrators face the potential for complete system compromise through arbitrary code execution, which could allow attackers to establish persistent access points, exfiltrate sensitive data, or deploy additional malware. The denial of service component creates additional operational challenges as device reloads can disrupt network connectivity and services, potentially affecting business operations across the organization. The vulnerability's impact extends beyond individual device compromise to potentially affecting network-wide availability and security posture, particularly in environments where multiple devices run the affected software versions. Organizations may experience service interruptions, security breaches, and compliance violations as a result of this vulnerability.
Mitigation strategies for CVE-2018-0315 should focus on immediate software updates and network segmentation approaches. Cisco has released patches addressing this vulnerability through software updates, making it essential for organizations to apply these fixes promptly to affected devices. Network administrators should prioritize patching critical infrastructure devices and implement network segmentation to limit the attack surface. The vulnerability's characteristics align with ATT&CK technique T1078 for Valid Accounts and T1499 for Endpoint Termination, indicating that exploitation could lead to both privilege escalation and system disruption. Organizations should also implement monitoring solutions to detect unusual authentication patterns and unauthorized access attempts. Additional defensive measures include disabling unnecessary AAA services, implementing strong access controls, and maintaining detailed network logs for forensic analysis in case of suspected exploitation attempts.