CVE-2004-2502 in Im-switch
Summary
by MITRE
im-switch before 11.4-46.1 in Fedora Core 2 allows local users to overwrite arbitrary files via a symlink attack on the imswitcher[PID] temporary file.
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Analysis
by VulDB Data Team • 12/07/2024
The vulnerability described in CVE-2004-2502 affects the im-switch component in Fedora Core 2 systems, specifically versions prior to 11.4-46.1. This issue represents a classic symlink attack scenario that exploits improper handling of temporary files during the switching of input methods in X Window System environments. The im-switch utility is responsible for managing input method configurations and switching between different input method handlers such as ibus, scim, or other input method daemons. The flaw occurs when the utility creates temporary files without proper security checks, making it susceptible to race conditions and symlink-based attacks.
The technical implementation of this vulnerability stems from the im-switch utility's insecure creation of temporary files with predictable naming patterns. When the utility executes, it generates temporary files named imswitcher[PID] where PID represents the process identifier. Local attackers can exploit this predictability by creating symbolic links with the same names in the target directory before the utility runs. This symlink attack allows the attacker to manipulate the temporary file creation process and ultimately overwrite arbitrary files on the system with the privileges of the user running im-switch. The vulnerability is categorized under CWE-377 as insecure temporary file creation and falls into the broader category of privilege escalation through file system manipulation.
The operational impact of this vulnerability extends beyond simple file overwriting capabilities, as it can be leveraged to escalate privileges within the system. Attackers with local access can potentially overwrite critical system files, configuration files, or even binaries that are executed with elevated privileges. This creates a significant risk for desktop environments where users might have legitimate access to the system but should not have the ability to modify system-critical components. The attack requires local system access but does not need network connectivity, making it particularly dangerous in multi-user environments where users might have legitimate access but could exploit this weakness to gain unauthorized access to system resources. The vulnerability aligns with ATT&CK technique T1068 by exploiting local system privileges and can be classified under T1548.1 for privilege escalation through file system manipulation.
Mitigation strategies for this vulnerability include updating to the patched version 11.4-46.1 or later, which implements proper temporary file handling with secure creation methods. System administrators should ensure that all packages are kept up to date and that the im-switch utility is properly configured to avoid predictable temporary file names. Additional protective measures include implementing proper file system permissions, using secure temporary file creation methods that check for existing symbolic links, and conducting regular security audits of system components that handle temporary files. The fix typically involves using functions like mkstemp() instead of creating files with predictable names, which prevents the symlink attack vector entirely. Organizations should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to critical system files that could result from such exploitation attempts.