CVE-2021-1127 in Enterprise NFV Infrastructure Software
Summary
by MITRE • 01/14/2021
A vulnerability in the web-based management interface of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface. The vulnerability is due to improper input validation of log file content stored on the affected device. An attacker could exploit this vulnerability by modifying a log file with malicious code and getting a user to view the modified log file. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or to access sensitive, browser-based information.
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Analysis
by VulDB Data Team • 02/13/2021
The vulnerability identified as CVE-2021-1127 represents a critical cross-site scripting flaw within Cisco Enterprise NFV Infrastructure Software NFVIS web interface. This issue affects the management capabilities of enterprise network virtualization solutions and demonstrates a fundamental weakness in input sanitization processes. The vulnerability exists specifically within the log file handling mechanism of the web-based management interface, where insufficient validation of user-supplied content allows malicious code execution. According to CWE-79, this classification encompasses the broad category of cross-site scripting vulnerabilities that occur when applications fail to properly validate or escape user-controllable data before incorporating it into web pages. The attack vector requires an authenticated session, meaning that an attacker must first establish valid credentials to the system, but once achieved, the impact extends to full browser-based code execution capabilities.
The technical exploitation mechanism leverages the improper input validation of log file content stored on the affected device. When log files contain malicious script code, and a user subsequently views these files through the vulnerable web interface, the embedded malicious code executes within the user's browser context. This creates a persistent threat where attackers can manipulate log files to inject malicious payloads that execute when legitimate users access the system. The vulnerability operates through the standard XSS attack pattern where unvalidated input flows into the web application's output mechanism, allowing attackers to execute arbitrary JavaScript in the context of the user's session. This particular flaw falls under the ATT&CK technique T1059.007 for Command and Scripting Interpreter, specifically targeting JavaScript execution within web browsers.
The operational impact of this vulnerability extends beyond simple code injection to potentially compromise entire user sessions and access sensitive browser-based information. Successful exploitation could enable attackers to access session cookies, steal user credentials, perform actions on behalf of authenticated users, or even redirect users to malicious websites. The vulnerability affects the core management interface of enterprise NFV infrastructure, which typically handles critical network operations and configuration management, making it a prime target for attackers seeking persistent access to enterprise network virtualization environments. Organizations using Cisco NFVIS platforms face significant risk as this vulnerability can be exploited by attackers who have gained initial access through other means, potentially leading to complete compromise of the virtualized network infrastructure.
Mitigation strategies for CVE-2021-1127 should focus on immediate patch application from Cisco, which addresses the root cause through proper input validation and sanitization of log file content. Network administrators should implement additional security controls including web application firewalls that can detect and block XSS attempts, regular monitoring of log file content for suspicious patterns, and strict access controls to limit authentication opportunities. The implementation of Content Security Policy headers can provide additional protection against XSS attacks by restricting script execution sources. Organizations should also consider regular security assessments of their web-based management interfaces and maintain comprehensive logging of all user activities within the management systems. According to industry best practices for web application security, this vulnerability highlights the critical need for input validation at all levels of application processing and demonstrates how seemingly benign features like log file viewing can become attack vectors when proper security controls are not implemented.