CVE-2016-6450 in IOS XE
Summary
by MITRE
A vulnerability in the package unbundle utility of Cisco IOS XE Software could allow an authenticated, local attacker to gain write access to some files in the underlying operating system. This vulnerability affects the following products if they are running a vulnerable release of Cisco IOS XE Software: Cisco 5700 Series Wireless LAN Controllers, Cisco Catalyst 3650 Series Switches, Cisco Catalyst 3850 Series Switches, Cisco Catalyst 4500E Series Switches, Cisco Catalyst 4500X Series Switches. More Information: CSCva60013 CSCvb22622. Known Affected Releases: 3.7(0) 16.4.1 Denali-16.1.3 Denali-16.2.2 Denali-16.3.1. Known Fixed Releases: 15.2(4)E3 16.1(2.208) 16.2(2.42) 16.3(1.22) 16.4(0.190) 16.5(0.29).
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Analysis
by VulDB Data Team • 10/04/2022
The vulnerability identified as CVE-2016-6450 represents a critical local privilege escalation flaw within Cisco IOS XE Software's unbundle utility component. This weakness specifically targets the file system permissions and access controls implemented within the operating system layer of affected network devices. The vulnerability arises from insufficient input validation and improper privilege handling during the decompression and extraction process of bundled files, creating a pathway for authenticated local attackers to escalate their privileges and gain unauthorized write access to critical system files. The affected product lineup includes enterprise-grade wireless controllers and switching equipment that form the backbone of many corporate and service provider networks, making this vulnerability particularly concerning from a security operations perspective.
Technical exploitation of this vulnerability requires an attacker to possess valid authentication credentials for the device, typically administrative access, but the flaw allows them to bypass normal file system restrictions and write to files that should normally be protected from modification. The unbundle utility, which is responsible for processing compressed files containing software updates or configuration data, fails to properly validate file paths and permissions during the extraction process, enabling attackers to manipulate the system's file structure. This flaw falls under the CWE-276 category of improper file permissions, specifically addressing inadequate access control mechanisms. The vulnerability's impact is amplified by the fact that it affects multiple product families within Cisco's IOS XE ecosystem, suggesting a systemic issue in the software's privilege management architecture.
The operational implications of this vulnerability extend beyond simple privilege escalation, as it could enable attackers to modify critical system components, install backdoors, or corrupt essential network services. Network administrators who rely on these devices for core infrastructure functions face significant risk, as an attacker with local access could potentially compromise the entire network segment managed by the affected device. The vulnerability's presence in multiple release versions indicates that Cisco's security team identified this as a persistent issue requiring coordinated remediation across their product line. The affected releases span several major versions including 15.2, 16.1, 16.2, 16.3, and 16.4, demonstrating that this flaw existed across a substantial portion of Cisco's IOS XE software lifecycle. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1068 which focuses on local privilege escalation and T1547 which addresses registry run keys and startup folder modifications, though the specific implementation here involves file system manipulation rather than registry changes.
Mitigation strategies for CVE-2016-6450 require immediate deployment of Cisco's security patches and updates to the affected software versions. Organizations should prioritize updating their Cisco 5700 Series Wireless LAN Controllers, Catalyst 3650, 3850, 4500E, and 4500X Series Switches to the fixed releases specified in the advisory. Network segmentation and least privilege access controls should be enforced to limit the potential impact of any successful exploitation attempts. Regular security assessments and vulnerability scanning should be implemented to identify any remaining unpatched systems within the network infrastructure. Additionally, monitoring for unauthorized file modifications and access attempts should be enhanced through security information and event management systems to detect potential exploitation attempts. The vulnerability highlights the importance of maintaining current security patches and implementing robust access controls for privileged accounts, as the attack vector requires legitimate administrative credentials to exploit, making credential protection and access monitoring essential defensive measures.