CVE-2015-1326 in python-dbusmock
Summary
by MITRE
python-dbusmock before version 0.15.1 AddTemplate() D-Bus method call or DBusTestCase.spawn_server_template() method could be tricked into executing malicious code if an attacker supplies a .pyc file.
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Analysis
by VulDB Data Team • 09/06/2023
The vulnerability identified as CVE-2015-1326 affects the python-dbusmock library version 0.15.1 and earlier, representing a critical security flaw in the handling of template execution within D-Bus mocking frameworks. This vulnerability stems from insufficient input validation and improper handling of Python bytecode files during the template processing phase. The flaw allows attackers to execute arbitrary code through malicious .pyc files that are loaded and executed by the vulnerable methods, specifically the AddTemplate() D-Bus method and the DBusTestCase.spawn_server_template() method. The issue arises from the library's trust model where it automatically executes code contained within template files without proper sanitization or verification of the bytecode integrity.
The technical implementation of this vulnerability leverages the inherent trust model of the python-dbusmock library where template files are processed and executed without adequate security checks. When an attacker crafts a malicious .pyc file and supplies it as a template parameter, the library's AddTemplate() method or spawn_server_template() method will load and execute this bytecode without proper validation. This creates a code execution vector where the attacker can inject malicious Python code that will run within the context of the application using the library. The vulnerability is particularly dangerous because it operates at the D-Bus method call level, allowing remote or local attackers to exploit it through legitimate interface interactions.
The operational impact of CVE-2015-1326 extends beyond simple code execution to encompass potential system compromise and privilege escalation scenarios. When exploited, this vulnerability can allow attackers to execute arbitrary commands on systems running vulnerable applications, potentially leading to complete system compromise. The attack surface is broad as it affects any application that uses python-dbusmock for testing or mocking D-Bus services, particularly in development environments or testing frameworks where such libraries are commonly deployed. The vulnerability is especially concerning in continuous integration environments where automated testing frameworks might be exposed to untrusted template inputs, creating potential for supply chain attacks.
Security mitigations for this vulnerability primarily involve upgrading to python-dbusmock version 0.15.1 or later, which includes proper input validation and sanitization of template files. Organizations should implement strict template file validation policies that reject or sanitize .pyc files before processing, and consider implementing additional security controls such as runtime code integrity checks and restricted execution environments. The vulnerability aligns with CWE-74 and CWE-94 categories related to improper neutralization of special elements and code injection, respectively, and maps to ATT&CK techniques involving privilege escalation and execution through legitimate system processes. Regular security assessments should verify that no vulnerable versions remain in production environments and that proper input validation mechanisms are in place to prevent similar issues in other components of the system architecture.