CVE-2017-6785 in Unified Communications Manager
Summary
by MITRE
A vulnerability in configuration modification permissions validation for Cisco Unified Communications Manager could allow an authenticated, remote attacker to perform a horizontal privilege escalation where one user can modify another user's configuration. The vulnerability is due to lack of proper Role Based Access Control (RBAC) when certain user configuration changes are requested. An attacker could exploit this vulnerability by sending an authenticated, crafted HTTP request to the targeted application. An exploit could allow the attacker to impact the integrity of the application where one user can modify the configuration of another user's information. Cisco Bug IDs: CSCve27331. Known Affected Releases: 10.5(2.10000.5), 11.0(1.10000.10), 11.5(1.10000.6).
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Analysis
by VulDB Data Team • 01/09/2021
The vulnerability identified as CVE-2017-6785 represents a critical access control flaw within Cisco Unified Communications Manager systems that undermines the fundamental security principles of role-based access control. This configuration modification permissions validation weakness allows authenticated remote attackers to perform horizontal privilege escalation, enabling one legitimate user to manipulate the configuration settings of other users within the same system. The vulnerability specifically manifests when certain user configuration changes are requested through the application's web interface, where proper access validation mechanisms fail to enforce the principle of least privilege. The flaw exists in the application's RBAC implementation, which should have prevented unauthorized cross-user configuration modifications but instead permitted such actions without adequate authorization checks. This represents a fundamental breakdown in the security architecture where user isolation is compromised, allowing attackers to potentially disrupt the integrity of the communication system and potentially gain unauthorized access to sensitive user information.
The technical exploitation of this vulnerability requires an authenticated attacker who can send crafted HTTP requests to the targeted Cisco Unified Communications Manager application. The attacker does not need to possess administrative privileges or elevated access rights, as the flaw allows them to leverage their existing user account to perform unauthorized configuration modifications. The vulnerability specifically affects versions 10.5(2.10000.5), 11.0(1.10000.10), and 11.5(1.10000.6) of the Cisco Unified Communications Manager software, indicating that the flaw was present across multiple release lines and persisted for an extended period. The attack vector operates through the web-based management interface, where the application fails to properly validate whether the requesting user has appropriate authorization to modify the target user's configuration parameters. This allows attackers to construct HTTP requests that bypass normal access controls and directly manipulate user settings, potentially including voice mail configurations, call routing settings, or other user-specific parameters that could impact system functionality or confidentiality.
The operational impact of this vulnerability extends beyond simple configuration modification and can significantly compromise the integrity and availability of the unified communications infrastructure. When one user can modify another user's configuration, the attacker gains the ability to disrupt communication services, potentially redirecting calls, modifying voice mail settings, or altering user access permissions. This capability creates a potential for service disruption, data integrity violations, and could enable further attacks within the network. The vulnerability particularly affects organizations that rely heavily on unified communications for business continuity, as unauthorized modifications could lead to critical communication failures or information disclosure. The impact is further compounded by the fact that this is a horizontal privilege escalation vulnerability, meaning that attackers can potentially move laterally within the system to compromise multiple user accounts without requiring additional authentication or elevated privileges. This makes the vulnerability particularly dangerous in environments where users have varying levels of access rights and where the integrity of user configurations is critical to maintaining proper system operation.
Organizations affected by this vulnerability should immediately implement mitigations including applying the relevant Cisco security patches and updates that address the RBAC validation flaw. The Cisco bug ID CSCve27331 specifically identifies this issue and should be referenced when applying the appropriate software fixes. Network segmentation and access control measures should be enhanced to limit the exposure of the unified communications manager to untrusted networks, while monitoring should be implemented to detect unauthorized configuration changes. Administrators should also review and validate user access rights to ensure that only authorized personnel have the ability to modify user configurations, implementing additional logging and auditing of configuration changes. The vulnerability aligns with CWE-284, which addresses improper access control, and represents a clear violation of the principle of least privilege that should be enforced in all enterprise systems. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques and could be leveraged as part of broader attack campaigns targeting communication infrastructure, potentially enabling more sophisticated attacks including data exfiltration or service disruption operations that could impact business continuity and operational security.