CVE-2014-1832 in Passenger
Summary
by MITRE
Phusion Passenger 4.0.37 allows local users to write to certain files and directories via a symlink attack on (1) control_process.pid or a (2) generation-* file. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-1831.
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Analysis
by VulDB Data Team • 04/16/2022
The vulnerability identified as CVE-2014-1832 affects Phusion Passenger version 4.0.37 and represents a significant security flaw that enables local users to manipulate critical system files through symbolic link attacks. This issue specifically targets two key file paths: control_process.pid and generation-* files, which are essential components in the Passenger application server's operation and process management. The vulnerability arises from an incomplete remediation of a previously identified flaw, CVE-2014-1831, demonstrating how rushed or inadequate security fixes can create persistent risks in software systems.
The technical implementation of this vulnerability involves a race condition or insecure file handling mechanism that allows attackers to create symbolic links in strategic locations before the legitimate system processes attempt to write to these files. When Passenger processes attempt to write to control_process.pid or generation-* files, they may inadvertently follow symbolic links to arbitrary locations on the filesystem, enabling unauthorized file creation, modification, or deletion. This type of attack falls under the category of symlink-based privilege escalation and file system manipulation attacks that have been documented in various security frameworks. The vulnerability directly relates to CWE-377, which addresses insecure temporary file handling, and CWE-378, which covers the creation of temporary files with insecure permissions.
The operational impact of this vulnerability extends beyond simple file manipulation as it can lead to privilege escalation, system compromise, and potential denial of service conditions within the Passenger application server environment. Local attackers who can execute code with the privileges of the Passenger process can leverage this vulnerability to gain unauthorized access to sensitive system resources, potentially allowing them to modify critical application files, inject malicious code, or establish persistent access points. The attack vector is particularly concerning because it requires minimal privileges and can be executed by any local user, making it a significant risk in multi-user environments where Passenger is deployed. This vulnerability directly maps to ATT&CK technique T1055, which covers privilege escalation through exploitation of software vulnerabilities.
Mitigation strategies for CVE-2014-1832 should focus on immediate patching of the Phusion Passenger software to the latest secure version that properly addresses the symlink handling issues. System administrators should also implement proper file system permissions and access controls around the Passenger installation directories, ensuring that temporary files and process control files are created with appropriate security attributes. Additional defensive measures include monitoring for suspicious file creation patterns, implementing proper file system auditing, and considering the use of file system capabilities such as immutable attributes for critical files. The vulnerability highlights the importance of thorough testing of security patches and the need for comprehensive vulnerability management processes that consider the potential for incomplete fixes to create new or persistent security risks in software systems.