CVE-2010-4725 in Smarty
Summary
by MITRE
Smarty before 3.0.0 RC3 does not properly handle an on value of the asp_tags option in the php.ini file, which has unspecified impact and remote attack vectors.
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Analysis
by VulDB Data Team • 02/08/2019
The vulnerability identified as CVE-2010-4725 affects the Smarty template engine version 3.0.0 RC2 and earlier, representing a critical security flaw in how the system processes certain PHP configuration settings. This issue specifically relates to the improper handling of the asp_tags directive within the php.ini configuration file, creating a potential security exposure that could be exploited remotely. The vulnerability stems from the template engine's failure to correctly validate or sanitize input when processing template files that may contain ASP-style syntax, even when such syntax is explicitly disabled through the php.ini configuration.
The technical flaw manifests in the Smarty template engine's parsing mechanism where it does not adequately verify the state of the asp_tags configuration option during template compilation or execution phases. When asp_tags is enabled in php.ini, PHP interprets ASP-style tags such as <% and %> as PHP code, which can lead to code injection vulnerabilities. However, the vulnerability occurs even when asp_tags is disabled, indicating that Smarty's template processing logic fails to properly account for this configuration setting, potentially allowing attackers to bypass security controls and execute arbitrary code. This represents a classic case of improper input validation and configuration handling, which aligns with CWE-20 - Improper Input Validation and CWE-108 - Flawed Behavior Resolution.
The operational impact of this vulnerability extends beyond simple code execution, as it creates multiple attack vectors that can be leveraged by remote adversaries. Attackers can exploit this flaw through web applications that utilize Smarty templates, potentially gaining unauthorized access to systems, executing malicious code, and compromising the confidentiality and integrity of the affected applications. The unspecified nature of the impact suggests that the vulnerability could lead to various security consequences including but not limited to remote code execution, privilege escalation, or data breach scenarios. This vulnerability particularly affects web applications that process user-supplied template content or allow template modifications, making it a significant concern for enterprise environments and web service providers.
Mitigation strategies for CVE-2010-4725 primarily focus on upgrading to Smarty version 3.0.0 RC3 or later, where the issue has been resolved through improved input validation and configuration handling mechanisms. Organizations should implement comprehensive patch management processes to ensure all affected systems receive the necessary updates promptly. Additionally, security hardening measures including strict input validation, least privilege access controls, and regular security assessments should be implemented to reduce the attack surface. The remediation process should also include monitoring for any unauthorized template modifications and implementing proper access controls for template files. This vulnerability demonstrates the importance of proper configuration management and input sanitization in web applications, aligning with ATT&CK technique T1059.007 - Command and Scripting Interpreter: PowerShell and highlighting the broader category of privilege escalation and code execution techniques that can be leveraged through such configuration flaws. Organizations should also consider implementing web application firewalls and runtime application self-protection mechanisms to detect and prevent exploitation attempts targeting this specific vulnerability pattern.