CVE-2009-0122 in hplip
Summary
by MITRE
hplip.postinst in HP Linux Imaging and Printing (HPLIP) 2.7.7 and 2.8.2 on Ubuntu allows local users to change the ownership of arbitrary files via unspecified manipulations in advance of an HPLIP installation or upgrade by an administrator, related to the product s attempt to correct the ownership of its configuration files within home directories.
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Analysis
by VulDB Data Team • 08/28/2019
The vulnerability identified as CVE-2009-0122 resides within the HP Linux Imaging and Printing (HPLIP) package version 2.7.7 and 2.8.2 running on Ubuntu systems. This issue manifests during the post-installation script execution phase, specifically within the hplip.postinst component that manages system configuration and file ownership during installation or upgrade processes. The flaw represents a privilege escalation vulnerability that allows local users to manipulate file ownership permissions through carefully crafted manipulations of the installation environment before administrator execution of HPLIP updates.
The technical root cause of this vulnerability stems from insufficient input validation and privilege checking within the post-installation script logic. When HPLIP attempts to correct ownership of configuration files within user home directories during installation or upgrade operations, the system fails to properly validate the integrity of file paths or verify that the current user possesses appropriate permissions to modify target files. This weakness creates an opportunity for malicious local users to pre-position files or directories in such a way that subsequent HPLIP installation processes will inadvertently change ownership of arbitrary system files to the attacker-controlled user account.
The operational impact of this vulnerability extends beyond simple file ownership manipulation, as it provides a potential pathway for local privilege escalation and system compromise. An attacker who gains local access to a system can exploit this vulnerability to modify critical system files or directories, potentially elevating their privileges to that of the root user or other high-privilege accounts. The vulnerability particularly affects systems where administrators regularly perform HPLIP package updates, as the attack vector requires pre-installation manipulation that can be executed by any local user with access to the system. This makes the vulnerability especially dangerous in multi-user environments where user accounts may have varying levels of system access.
Security professionals should note that this vulnerability aligns with CWE-276, which addresses improper file permissions, and represents a specific case of inadequate privilege checking during system administration operations. The attack pattern follows elements of the ATT&CK framework's privilege escalation techniques, specifically targeting post-installation script execution phases where system permissions are modified. Organizations should implement immediate mitigation strategies including restricting local user access to system installation directories, monitoring for unauthorized file ownership changes, and ensuring that all system updates are performed by privileged users with proper access controls. The vulnerability underscores the critical importance of validating file integrity and proper privilege management during package installation processes, particularly for system administration tools that modify critical system files and directory permissions.