CVE-2015-3436 in Collaboration Platform
Summary
by MITRE
provider/server/ECServer.cpp in Zarafa Collaboration Platform (ZCP) before 7.1.13 and 7.2.x before 7.2.1 allows local users to write to arbitrary files via a symlink attack on /tmp/zarafa-upgrade-lock.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 11/25/2024
The vulnerability identified as CVE-2015-3436 resides within the Zarafa Collaboration Platform, specifically in the ECServer.cpp component located in the provider/server directory. This issue affects versions prior to 7.1.13 and 7.2.x prior to 7.2.1, creating a significant security risk for organizations utilizing this email and collaboration platform. The flaw manifests as a local privilege escalation opportunity that stems from improper handling of temporary files during the upgrade process, making it particularly dangerous in environments where local user access is possible.
The technical implementation of this vulnerability exploits a race condition in the upgrade mechanism where the application creates a temporary file at /tmp/zarafa-upgrade-lock without proper validation of the file's existence or ownership. Local attackers can leverage this by creating a symbolic link at the same location, pointing to a sensitive file they wish to modify. When the upgrade process executes and attempts to write to what it believes is the temporary file, it actually writes to the target file specified by the symbolic link. This represents a classic symlink attack pattern that violates proper file access controls and can lead to unauthorized modification of critical system files or configuration data.
The operational impact of this vulnerability extends beyond simple file modification, as it provides local users with a potential pathway to escalate privileges and compromise the integrity of the Zarafa server. Attackers could use this technique to modify configuration files, inject malicious code, or manipulate system settings that would otherwise require administrative privileges. The attack vector is particularly concerning because it does not require network access or remote exploitation capabilities, making it accessible to anyone with local shell access to the system. This vulnerability aligns with CWE-377: Insecure Temporary File and CWE-367: Time-of-Check Time-of-Use (TOCTOU) Race Condition, both of which are fundamental security issues that undermine the integrity of file operations in Unix-like systems.
Organizations should immediately implement mitigations including upgrading to the patched versions 7.1.13 and 7.2.1, which address the race condition by implementing proper file validation and atomic operations during the upgrade process. Additional protective measures include restricting local user access to the Zarafa server, implementing proper file permissions for the /tmp directory, and monitoring for unauthorized symbolic link creation in critical system locations. The remediation process should also involve verifying that no symbolic links exist at the vulnerable path and ensuring that temporary file creation uses secure methods such as mkstemp() or similar atomic operations that prevent symlink attacks. This vulnerability demonstrates the critical importance of secure file handling practices and proper privilege separation in server applications, aligning with ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1548.001 for Abuse of Functionality, as it enables attackers to leverage legitimate system functionality for malicious purposes.