CVE-2008-0376 in Small Axe Weblog
Summary
by MITRE
PHP remote file inclusion vulnerability in inc/linkbar.php in Small Axe Weblog 0.3.1 allows remote attackers to execute arbitrary PHP code via a URL in the cfile parameter.
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Analysis
by VulDB Data Team • 10/14/2024
The vulnerability identified as CVE-2008-0376 represents a critical remote file inclusion flaw within the Small Axe Weblog 0.3.1 content management system that exposes web applications to arbitrary code execution attacks. This vulnerability specifically affects the inc/linkbar.php component where user-supplied input is improperly validated and directly incorporated into file inclusion operations. The flaw exists in the cfile parameter which accepts URL values without adequate sanitization, creating an avenue for malicious actors to inject and execute arbitrary PHP code on the target server. The vulnerability stems from the application's failure to implement proper input validation and sanitization mechanisms, allowing attackers to manipulate the file inclusion process through crafted malicious URLs.
This security weakness aligns with CWE-98, which categorizes improper neutralization of special elements in output used by a downstream component as a remote file inclusion vulnerability. The attack vector operates through the manipulation of the cfile parameter where an attacker can supply a malicious URL that gets included by the vulnerable application. The vulnerability is classified as a remote code execution flaw under the MITRE ATT&CK framework's technique T1059.007, which covers the use of remote code execution capabilities to gain unauthorized access to systems. The flaw demonstrates a classic example of insecure direct object reference vulnerability where user input directly controls file inclusion operations without proper validation or access control checks.
The operational impact of this vulnerability is severe as it provides attackers with complete control over the affected web server. Successful exploitation enables adversaries to execute arbitrary PHP code, upload malicious files, establish persistent backdoors, and potentially escalate privileges within the compromised environment. The vulnerability affects the confidentiality, integrity, and availability of the web application and underlying system resources. Attackers can leverage this flaw to deploy web shells, exfiltrate sensitive data, modify content, and use the compromised server as a launch point for further attacks against internal networks. The vulnerability also poses significant risk to other applications running on the same server due to potential privilege escalation and lateral movement opportunities.
Mitigation strategies for CVE-2008-0376 require immediate implementation of multiple defensive measures including input validation and sanitization of all user-supplied parameters, particularly those used in file inclusion operations. The most effective immediate fix involves disabling the ability to include remote files by setting the allow_url_fopen directive to off in the php.ini configuration file and removing the vulnerable include statement from the linkbar.php file. Organizations should implement proper parameter validation that rejects any non-local file paths and restricts file inclusion to predefined safe directories. Additionally, the application should be updated to a patched version that properly validates and sanitizes the cfile parameter before any file inclusion operations occur. Network-level protections including web application firewalls and intrusion detection systems should be configured to monitor and block suspicious URL patterns targeting this vulnerability. Regular security audits and code reviews should be conducted to identify similar insecure coding practices that could lead to remote file inclusion vulnerabilities in other components of the web application ecosystem.