CVE-2014-8166 in CUPS
Summary
by MITRE
The browsing feature in the server in CUPS does not filter ANSI escape sequences from shared printer names, which might allow remote attackers to execute arbitrary code via a crafted printer name.
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Analysis
by VulDB Data Team • 03/04/2025
The vulnerability identified as CVE-2014-8166 resides within the Common Unix Printing System CUPS server implementation, specifically affecting the browsing feature that displays shared printer names. This flaw represents a critical security oversight in how the system handles user-provided printer names, particularly when these names contain ANSI escape sequences that are typically used for terminal formatting and control. The issue stems from insufficient input validation and sanitization within the server's browsing functionality, creating a pathway for malicious actors to inject potentially harmful sequences that could be interpreted by terminal emulators or other components that process these names.
The technical exploitation of this vulnerability occurs when an attacker crafts a printer name containing specially formatted ANSI escape sequences that, when displayed in the browsing interface, could trigger unintended behavior in terminal applications or web browsers that render these names. These sequences can manipulate terminal display properties, control cursor positioning, or even execute commands when processed by vulnerable applications. The vulnerability manifests because the CUPS server fails to properly sanitize or filter these sequences before displaying them in the browsing interface, allowing the escape codes to be interpreted by client applications that consume the printer names. This represents a classic case of insufficient input sanitization, categorized under CWE-15 which deals with improper neutralization of input during web application development.
The operational impact of this vulnerability extends beyond simple display manipulation, as it creates a potential remote code execution vector that could be leveraged by attackers in various attack scenarios. When a user browses shared printers on a network, the printer names are displayed in the interface, and if one of those names contains malicious ANSI escape sequences, the sequences could be executed by terminal applications or web browsers that render these names. This could enable attackers to execute arbitrary commands on systems where the browsing interface is accessed, particularly in environments where users might be browsing from terminal-based applications or web interfaces that do not properly isolate these sequences. The attack surface is particularly concerning in enterprise environments where multiple users might access shared printer browsing features, creating opportunities for privilege escalation or system compromise.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input sanitization and filtering mechanisms within the CUPS server, specifically targeting ANSI escape sequences and other potentially dangerous character patterns. Organizations should ensure that all user-provided printer names are properly validated and sanitized before being displayed in browsing interfaces, removing or encoding any escape sequences that could be interpreted by terminal applications. The implementation should follow established security practices such as those outlined in the OWASP Input Validation Cheat Sheet and should incorporate regular expression filtering to identify and neutralize problematic sequences. Additionally, system administrators should consider implementing network segmentation and access controls to limit exposure of the CUPS browsing feature to trusted users only, while also monitoring for unusual printer name registrations that might indicate attempted exploitation. The vulnerability aligns with ATT&CK technique T1059 which covers command and scripting interpreter usage, and T1068 which deals with exploit for privilege escalation, making it particularly dangerous in environments where untrusted users can register printers or where the browsing interface is accessible from systems with elevated privileges.