CVE-2015-2265 in cups-filters
Summary
by MITRE
The remove_bad_chars function in utils/cups-browsed.c in cups-filters before 1.0.66 allows remote IPP printers to execute arbitrary commands via consecutive shell metacharacters in the (1) model or (2) PDL. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-2707.
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Analysis
by VulDB Data Team • 05/01/2022
The vulnerability identified as CVE-2015-2265 represents a critical command injection flaw within the cups-filters package, specifically affecting versions prior to 1.0.66. This issue resides in the remove_bad_chars function located within the utils/cups-browsed.c file, which is part of the Internet Printing Protocol (IPP) printer browsing functionality. The vulnerability emerges from an insufficient sanitization mechanism that fails to properly handle shell metacharacters, creating a pathway for remote code execution through IPP printer configurations. The flaw is particularly concerning because it builds upon a previous vulnerability CVE-2014-2707, indicating a pattern of incomplete remediation efforts that leave systems exposed to persistent attack vectors.
The technical implementation of this vulnerability exploits the improper handling of printer model and PDL (Page Description Language) attributes during IPP printer discovery and configuration processes. When cups-browsed processes printer information from remote IPP printers, the remove_bad_chars function attempts to sanitize input but fails to adequately filter consecutive shell metacharacters. This allows attackers to inject malicious commands that get executed within the shell context of the cups-browsed process, which typically runs with elevated privileges. The vulnerability operates at the protocol level where IPP printers communicate their capabilities and attributes, making it possible for an attacker to compromise systems simply by configuring a malicious printer that appears legitimate within the network.
The operational impact of CVE-2015-2265 extends beyond simple remote code execution to encompass complete system compromise capabilities. Since the cups-browsed daemon often runs with administrative privileges and interacts with system resources through shell commands, successful exploitation can lead to full system takeover, data exfiltration, and persistence mechanisms. Attackers can leverage this vulnerability to execute arbitrary commands with the privileges of the cups-browsed process, potentially gaining access to network resources, installing backdoors, or conducting further reconnaissance. The vulnerability affects environments where IPP printer browsing is enabled, which includes most modern printing infrastructures that support automatic printer discovery and configuration.
Organizations should implement immediate mitigations including upgrading to cups-filters version 1.0.66 or later, which contains the corrected sanitization logic. Network segmentation and firewall rules should be configured to restrict IPP printer communication to trusted networks only, limiting the attack surface. Additionally, monitoring should be implemented to detect unusual printer configuration changes or command execution patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-77 and CWE-94 categories, representing both improper neutralization of special elements used in command execution and code injection flaws. From an ATT&CK framework perspective, this vulnerability maps to T1059 (Command and Scripting Interpreter) and T1068 (Exploitation for Privilege Escalation), demonstrating how printer browsing functionality can be weaponized for system compromise. Security teams should also consider implementing input validation at multiple layers and conducting regular security assessments of printing infrastructure to prevent similar issues from arising due to incomplete vulnerability remediation processes.