CVE-2008-5370 in pvpgn
Summary
by MITRE
pvpgn-support-installer in pvpgn 1.8.1 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/pvpgn-support-1.0.tar.gz temporary file.
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Analysis
by VulDB Data Team • 10/19/2018
The vulnerability identified as CVE-2008-5370 resides within the pvpgn-support-installer component of the pvpgn 1.8.1 software suite, representing a classic symlink attack scenario that enables local privilege escalation through arbitrary file overwrite capabilities. This flaw specifically targets the temporary file handling mechanism where the installer creates a temporary archive file at /tmp/pvpgn-support-1.0.tar.gz without proper validation of the file's existence or ownership, creating a window of opportunity for malicious actors to manipulate the installation process.
The technical implementation of this vulnerability stems from inadequate temporary file creation practices that violate fundamental security principles outlined in the CWE-354 weakness category, specifically CWE-354: Improper Check for Unusual or Exceptional Conditions. The installer routine fails to verify whether the target temporary file is a symbolic link or if it already exists, allowing an attacker to establish a symlink pointing to a critical system file or configuration target before the legitimate installation process attempts to write to the temporary location. This insecure temporary file handling pattern directly aligns with the ATT&CK technique T1059.007: Command and Scripting Interpreter - PowerShell, where attackers leverage system-level vulnerabilities to execute malicious code through legitimate system tools.
The operational impact of this vulnerability extends beyond simple file overwrites, as it provides attackers with a mechanism to escalate privileges and potentially compromise the entire system. When the installer executes and attempts to write to the temporary file location, the system follows the symlink to the attacker-controlled target, resulting in arbitrary file modification or replacement. This capability can be exploited to modify system binaries, configuration files, or even create backdoor entries within the system, making it particularly dangerous in environments where the installer runs with elevated privileges. The vulnerability affects systems where local users have access to the installation process, potentially enabling privilege escalation from standard user accounts to administrative privileges.
Mitigation strategies for this vulnerability must address the root cause of insecure temporary file handling through multiple layers of defense. The most effective immediate solution involves modifying the installer to implement proper temporary file creation using secure methods such as creating files with exclusive access permissions or using the mkstemp() system call which ensures atomic creation of temporary files. Organizations should also implement privilege separation techniques where installation processes run with minimal required privileges and avoid running installation scripts with elevated permissions when possible. Additionally, system administrators should conduct regular security audits to identify and remediate similar insecure temporary file handling patterns in other software components, as this vulnerability type commonly appears in legacy applications that have not been updated to follow modern security practices. The remediation approach should also include implementing proper file system permissions and monitoring for suspicious symlink creation activities in temporary directories to detect potential exploitation attempts.