CVE-2017-6708 in Ultra Services Framework
Summary
by MITRE
A vulnerability in the symbolic link (symlink) creation functionality of the AutoVNF tool for the Cisco Ultra Services Framework could allow an unauthenticated, remote attacker to read sensitive files or execute malicious code on an affected system. The vulnerability is due to the absence of validation checks for the input that is used to create symbolic links. This vulnerability affects all releases of the Cisco Ultra Services Framework prior to Releases 5.0.3 and 5.1. Cisco Bug IDs: CSCvc76654.
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Analysis
by VulDB Data Team • 12/30/2020
The vulnerability identified as CVE-2017-6708 resides within the AutoVNF tool component of Cisco Ultra Services Framework, representing a critical security flaw that undermines the integrity of symbolic link creation processes. This weakness manifests in the absence of proper input validation mechanisms during symbolic link generation, creating an exploitable condition that can be leveraged by remote attackers without authentication requirements. The vulnerability specifically targets the symbolic link functionality that is integral to the framework's operational capabilities, making it a significant concern for organizations relying on Cisco's Ultra Services Framework for their network infrastructure management.
The technical root cause of this vulnerability stems from insufficient validation of user-supplied input parameters that are utilized in the creation of symbolic links within the AutoVNF tool. When the system processes requests to create symbolic links, it fails to implement proper sanitization or verification checks on the input data, allowing malicious actors to inject crafted parameters that can manipulate the symbolic link creation process. This lack of input validation creates a path for attackers to potentially traverse file system boundaries and access unauthorized resources, as the system does not properly validate whether the requested symbolic link targets are legitimate or pose security risks. The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks, and demonstrates how inadequate input validation can lead to arbitrary file access.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially enable remote code execution capabilities within affected systems. An attacker exploiting this vulnerability could gain unauthorized access to sensitive files, system configurations, or other critical data stored within the affected framework. The remote nature of the attack means that threat actors do not require physical access or local credentials to exploit the vulnerability, making it particularly dangerous for networked environments. This vulnerability affects all releases of Cisco Ultra Services Framework prior to versions 5.0.3 and 5.1, indicating that organizations using older releases remain exposed to this risk. The potential for privilege escalation and data compromise makes this vulnerability particularly concerning for enterprises relying on Cisco's Ultra Services Framework for their service delivery platforms.
Mitigation strategies for CVE-2017-6708 should focus on immediate deployment of the vendor-provided security patches and updates for Cisco Ultra Services Framework, specifically targeting releases 5.0.3 and 5.1 or later versions. Organizations should implement network segmentation and access controls to limit exposure of affected systems to untrusted networks or users. Security monitoring should be enhanced to detect anomalous symbolic link creation activities that might indicate exploitation attempts. Additionally, implementing proper input validation and sanitization processes for all symbolic link operations within the framework can provide defense-in-depth measures against similar vulnerabilities. The ATT&CK framework categorizes this vulnerability under T1059 for command and scripting interpreter and T1078 for valid accounts, as exploitation may involve leveraging legitimate system access to execute malicious commands through symbolic link manipulation. Organizations should also consider implementing automated patch management solutions to ensure timely deployment of security updates and reduce the window of exposure for known vulnerabilities.