CVE-2016-1403 in IP 8800
Summary
by MITRE
CISCO IP 8800 phones with software 11.0.1 and earlier allow local users to gain privileges for OS command execution via crafted CLI commands, aka Bug ID CSCuz03005.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/03/2019
The vulnerability identified as CVE-2016-1403 affects Cisco IP 8800 series phones running software versions 11.0.1 and earlier, representing a critical privilege escalation flaw that enables local attackers to execute arbitrary operating system commands. This vulnerability resides within the command line interface implementation of the affected telephony devices, specifically targeting the authentication and authorization mechanisms that govern CLI command execution. The flaw allows an attacker with local access to the device to craft malicious CLI commands that bypass normal security restrictions and elevate their privileges to execute system-level operations. This represents a significant security weakness in enterprise communication infrastructure where physical access to endpoints may be compromised.
The technical root cause of this vulnerability stems from inadequate input validation and privilege management within the CLI processing subsystem of the Cisco IP 8800 phones. When legitimate CLI commands are processed, the system fails to properly sanitize or validate user input before executing operations that could affect system-level functionality. The vulnerability specifically manifests when certain CLI commands are constructed in a particular manner that exploits the underlying command parsing logic, allowing attackers to inject malicious payloads that are subsequently executed with elevated privileges. This flaw operates at the application layer within the phone's operating system, typically affecting the embedded Linux-based environment that powers these communication devices.
From an operational impact perspective, this vulnerability poses substantial risk to enterprise networks as it allows local attackers to gain unauthorized system-level access to telephony infrastructure. The implications extend beyond simple command execution, as successful exploitation could enable attackers to modify phone configurations, intercept communications, or establish persistent access points within the network. Network administrators face the challenge of securing endpoints that may be physically accessible to unauthorized personnel, particularly in environments where phone devices are located in open office spaces or other accessible areas. The vulnerability's local nature means that physical access to the device is required for exploitation, but this access vector is often more attainable than remote attack vectors, especially in environments where physical security controls are inadequate.
Organizations should implement immediate mitigation strategies including upgrading to Cisco software versions that address this vulnerability, specifically those released after the patch availability date for CSCuz03005. The recommended approach involves deploying firmware updates that correct the CLI command processing logic and strengthen privilege validation mechanisms. Network segmentation and access controls should be enhanced to limit physical access to telephony devices, particularly in areas where unauthorized personnel might gain access. Security monitoring should include detection of unusual CLI activity patterns that might indicate exploitation attempts, while regular vulnerability assessments should be conducted to identify other potential weaknesses in telephony infrastructure. This vulnerability aligns with CWE-20, which describes improper input validation, and represents a typical example of how insufficient privilege separation can lead to privilege escalation attacks. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting local system commands and operating system commands as attack vectors. Organizations should also consider implementing network-based security controls to monitor and restrict CLI access to telephony infrastructure, particularly in environments where physical security controls may be insufficient to prevent unauthorized access.