CVE-2015-6265 in Application Control Engine
Summary
by MITRE
The CLI in Cisco Application Control Engine (ACE) 4700 A5 3.0 and earlier allows local users to bypass intended access restrictions, and read or write to files, by entering an unspecified CLI command with a crafted file as this command's input, aka Bug ID CSCur23662.
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Analysis
by VulDB Data Team • 06/13/2022
The vulnerability described in CVE-2015-6265 affects the Command Line Interface of Cisco Application Control Engine (ACE) version 4700 A5 3.0 and earlier systems, representing a critical authorization bypass flaw that undermines the security model of the device. This issue specifically targets the CLI implementation within the ACE platform, which serves as the primary administrative interface for configuring and managing the application control engine. The vulnerability stems from insufficient input validation and access control mechanisms within the CLI parser, allowing local authenticated users to exploit a weakness in command processing that enables arbitrary file operations. The flaw manifests when a crafted file is provided as input to an unspecified CLI command, creating a path for unauthorized file access that violates the intended security boundaries of the system. This represents a significant compromise in the principle of least privilege, as local users who have already gained access to the system can escalate their privileges to perform operations that should be restricted to administrative personnel or system processes.
The technical implementation of this vulnerability involves a command injection or manipulation flaw within the CLI processing layer where the system fails to properly validate or sanitize file paths and command inputs before executing operations. According to CWE classification, this vulnerability maps to CWE-22, which describes Improper Limitation of a Pathname to a Restricted Directory, and CWE-284, which covers Improper Access Control. The attack vector specifically targets the ACE's file system access controls through the CLI interface, where the system's inability to properly validate user-supplied file names and paths allows malicious input to bypass normal access restrictions. This flaw operates at the application level and leverages the trust relationship between the CLI and underlying file system operations, where legitimate administrative commands become vulnerable to manipulation by attackers who understand the system's command structure and file access patterns. The unspecified nature of the CLI command in the vulnerability description suggests that multiple command interfaces within the ACE system may be susceptible to this manipulation, indicating a systemic weakness rather than an isolated flaw.
The operational impact of CVE-2015-6265 extends beyond simple unauthorized file access to potentially enable complete system compromise when combined with other attack vectors. Local users who exploit this vulnerability can read sensitive configuration files, system logs, and potentially modify critical system components that control application behavior and network traffic management. This access capability allows for information disclosure, privilege escalation, and potential denial of service conditions that could disrupt application control services for enterprise networks. The vulnerability affects organizations that rely on ACE appliances for application delivery and traffic management, creating a risk that could lead to unauthorized access to corporate applications, data exfiltration, and disruption of critical network services. From an attacker's perspective, this vulnerability represents a low-effort path to system compromise that can be exploited without requiring external network access, making it particularly dangerous in environments where local access is possible. The impact is further amplified when considering that ACE appliances often serve as critical network infrastructure components that control application availability and security policies for enterprise environments.
Organizations affected by CVE-2015-6265 should implement immediate mitigations including applying the vendor-provided security patches and updates that address the CLI input validation issues. The recommended approach involves upgrading to Cisco ACE software versions that contain fixes for the specific command processing flaws identified in the vulnerability. Network administrators should also implement additional controls such as restricting local access to ACE appliances, implementing strict access controls for CLI sessions, and monitoring for unusual file access patterns that may indicate exploitation attempts. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, where adversaries leverage legitimate system tools to execute malicious commands. Security monitoring should focus on detecting unauthorized file read or write operations through the CLI, particularly when these operations occur from unexpected sources or at unusual times. Organizations should also consider implementing principle of least privilege controls that limit local user access to only necessary administrative functions, reducing the potential impact of such vulnerabilities. The vulnerability serves as a reminder of the critical importance of input validation and access control in system interfaces, particularly in network infrastructure devices where unauthorized access can have widespread consequences for enterprise security and operations.