CVE-2017-6680 in Ultra Services Framework
Summary
by MITRE
A vulnerability in the AutoVNF logging function of Cisco Ultra Services Framework could allow an unauthenticated, remote attacker to create arbitrary directories on the affected system. More Information: CSCvc76652. Known Affected Releases: 21.0.0.
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-6680 resides within the AutoVNF logging functionality of Cisco Ultra Services Framework version 21.0.0, presenting a critical security risk that enables unauthenticated remote attackers to manipulate the file system through arbitrary directory creation. This flaw specifically targets the logging mechanisms implemented within the framework, which is designed to handle virtual network function operations and service delivery. The issue stems from inadequate input validation and access control measures within the logging subsystem, allowing malicious actors to exploit the system's directory creation capabilities without proper authentication or authorization.
The technical exploitation of this vulnerability involves an attacker leveraging the AutoVNF logging function to execute directory creation commands that bypass normal security controls. This represents a directory traversal and privilege escalation vulnerability that aligns with CWE-22, which catalogs improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks. The flaw operates by accepting user-controllable input that is not properly sanitized before being used in file system operations, enabling the attacker to specify arbitrary directory paths that the system will attempt to create. This vulnerability is particularly dangerous because it allows for the creation of directories in locations where the application process has write permissions, potentially leading to further exploitation opportunities.
Operationally, this vulnerability can have severe consequences for organizations relying on Cisco Ultra Services Framework for their network infrastructure management. The ability to create arbitrary directories provides attackers with a foothold for more sophisticated attacks, including potential privilege escalation, persistent backdoor establishment, and data exfiltration capabilities. Attackers could use this vulnerability to create directories in system locations, potentially interfering with legitimate system operations, installing malicious components, or establishing persistent access points. The remote nature of the attack means that threat actors can exploit this vulnerability from outside the network perimeter without requiring any credentials, making it particularly dangerous for cloud-based deployments and services that expose the framework to external networks.
The impact of this vulnerability extends beyond simple directory creation capabilities, as it can serve as a stepping stone for more comprehensive attacks within the network environment. According to ATT&CK framework, this vulnerability maps to T1059 Command and Scripting Interpreter and T1078 Valid Accounts, as it enables attackers to establish persistence and potentially escalate privileges through the manipulation of system directories. Organizations utilizing Cisco Ultra Services Framework should implement immediate mitigations including network segmentation to limit access to affected systems, disabling unnecessary logging functions, and applying the latest security patches provided by Cisco. Additionally, monitoring for unusual directory creation patterns in system logs should be implemented as part of the defensive strategy, as this activity would be indicative of exploitation attempts. The vulnerability also underscores the importance of proper input validation and access control mechanisms in service frameworks, particularly those handling sensitive network operations and virtualized network functions.