CVE-2019-12667 in IOS XE
Summary
by MITRE
A vulnerability in the web framework code of Cisco IOS XE Software could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the web interface of the affected software. The vulnerability is due to insufficient input validation of some parameters that are passed to the web server of the affected software. An attacker could exploit this vulnerability by convincing a user of the web interface to access a malicious link or by intercepting a user request for the affected web interface and injecting malicious code into the request. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected web interface or allow the attacker to access sensitive browser-based information.
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Analysis
by VulDB Data Team • 12/28/2023
The vulnerability identified as CVE-2019-12667 represents a critical stored cross-site scripting flaw within Cisco IOS XE Software web framework components. This weakness resides in the insufficient validation of input parameters processed by the web server interface, creating an attack vector that can be exploited by authenticated remote adversaries. The vulnerability specifically affects the web-based management interface of Cisco IOS XE devices, which are widely deployed across enterprise networks for routing and switching operations. The flaw stems from inadequate sanitization of user-supplied data that flows through the web server's parameter handling mechanisms, allowing malicious payloads to be stored and subsequently executed when legitimate users interact with the affected interface. This type of vulnerability is particularly dangerous because it can persist across multiple user sessions and can be leveraged to compromise the integrity of the web interface and the data it processes.
The technical exploitation of CVE-2019-12667 requires an attacker to first authenticate to the affected web interface, which reduces the attack surface but does not eliminate the risk entirely. Attackers can leverage this vulnerability through two primary methods: by crafting malicious links that, when clicked by an authenticated user, trigger the XSS payload, or by intercepting and modifying legitimate user requests to inject malicious code. The stored nature of this vulnerability means that once malicious input is accepted and processed by the vulnerable web framework, it remains persistent within the system until actively removed. This characteristic makes the vulnerability particularly insidious as it can affect multiple users over time without requiring repeated exploitation attempts. The attack vectors align with ATT&CK technique T1059.001 for command and scripting interpreter and T1566.001 for spearphishing via social engineering, demonstrating how this vulnerability can be weaponized in broader attack campaigns.
The operational impact of CVE-2019-12667 extends beyond simple script execution, as it can potentially lead to complete compromise of the web interface and associated administrative functions. Successful exploitation allows attackers to execute arbitrary code within the context of the web interface, which could enable them to access sensitive browser-based information, modify web interface functionality, or even escalate privileges within the affected system. The vulnerability creates a persistent threat vector that can be used to establish backdoors, steal session cookies, or redirect users to malicious sites. Organizations using affected Cisco IOS XE software face significant risk to their network management infrastructure, as the web interface often provides access to critical network configuration and monitoring functions. This vulnerability can undermine the security posture of entire networks, particularly when the affected devices serve as primary management points for large enterprise deployments.
Cisco has released patches and software updates to address this vulnerability, which should be applied immediately to all affected systems. Organizations should implement network segmentation to limit access to the web interface, restrict authentication to trusted networks, and employ web application firewalls to detect and prevent malicious payloads. The remediation process should include thorough testing of patches in controlled environments before deployment to production systems. Security monitoring should focus on detecting anomalous web interface access patterns, unusual parameter inputs, and potential exploitation attempts. This vulnerability highlights the importance of input validation and output encoding in web applications, aligning with CWE-79 which specifically addresses cross-site scripting flaws. Organizations should also consider implementing multi-factor authentication for web interface access and regular security assessments of their network management interfaces to identify similar vulnerabilities in other components of their infrastructure.