CVE-2021-1399 in Unified Communications Manager
Summary
by MITRE • 04/08/2021
A vulnerability in the Self Care Portal of Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an authenticated, remote attacker to modify data on an affected system without proper authorization. The vulnerability is due to insufficient validation of user-supplied data to the Self Care Portal. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected system. A successful exploit could allow the attacker to modify information without proper authorization.
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Analysis
by VulDB Data Team • 04/11/2021
The vulnerability identified as CVE-2021-1399 represents a critical authorization bypass issue within Cisco's unified communications infrastructure, specifically affecting the Self Care Portal component of both Cisco Unified Communications Manager and its Session Management Edition. This flaw resides in the fundamental data validation mechanisms that govern user interactions with the system's administrative interface, creating a pathway for malicious actors to manipulate system data through legitimate authentication channels. The vulnerability demonstrates a classic case of inadequate input validation where the system fails to properly verify the integrity and authenticity of data submitted by authenticated users, thereby undermining the security model that should protect against unauthorized modifications.
The technical exploitation of CVE-2021-1399 leverages the insufficient validation of user-supplied data within the Self Care Portal's HTTP request processing pipeline. Attackers can craft specifically designed HTTP requests that bypass normal authorization checks, allowing them to manipulate system configurations and data without proper administrative privileges. This type of vulnerability falls under the CWE-20 category of "Improper Input Validation" and aligns with ATT&CK technique T1078.004 for Valid Accounts and T1566.001 for Phishing, as it requires authentication but then enables privilege escalation through data manipulation. The flaw essentially creates a backdoor within the legitimate authentication process, allowing attackers to perform unauthorized modifications while maintaining the appearance of legitimate system usage.
From an operational perspective, the impact of this vulnerability extends beyond simple data modification to encompass potential system compromise and service disruption within enterprise communications environments. Organizations utilizing affected Cisco Unified Communications Manager systems face significant risk as attackers could alter critical telephony configurations, modify user accounts, or manipulate system settings that govern call routing, voicemail systems, and other essential communication services. The vulnerability's remote exploitation capability means that attackers do not require physical access to the network, making it particularly dangerous in environments where network segmentation is not properly implemented. This weakness could lead to service degradation, unauthorized access to sensitive communication channels, and potential data exfiltration through manipulation of the underlying communication infrastructure.
Organizations should immediately implement mitigation strategies including applying the latest security patches from Cisco, implementing network segmentation to isolate the affected systems, and conducting thorough access reviews to ensure only authorized personnel maintain access to the Self Care Portal. The vulnerability underscores the importance of proper input validation and authorization checks within web applications, particularly those handling sensitive administrative functions. Security teams should also consider implementing additional monitoring and logging of administrative activities to detect potential exploitation attempts. This vulnerability serves as a reminder of the critical need for comprehensive security testing, including penetration testing and code reviews, to identify and remediate similar validation weaknesses in enterprise communication systems. The affected systems should also be configured with appropriate firewall rules and access controls to limit exposure to unauthorized users while maintaining operational functionality.