CVE-2005-0778 in PhotoPost PHP Pro
Summary
by MITRE
PhotoPost PHP 5.0 RC3 does not fully verify that an uploaded file is an image file, which allows remote attackers to inject arbitrary Javascript by uploading non-image files with an image extension such as .gif.
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Analysis
by VulDB Data Team • 06/18/2019
PhotoPost PHP version 5.0 RC3 contains a critical security vulnerability that stems from insufficient validation of uploaded file types during the image upload process. This flaw represents a classic example of insecure file upload handling that can be categorized under CWE-434, which specifically addresses "Unrestricted Upload of File with Dangerous Type." The vulnerability exists because the application fails to perform comprehensive verification of file content rather than relying solely on file extension checks. Attackers can exploit this weakness by uploading malicious files with image file extensions such as .gif, .jpg, or .png while the actual file content contains embedded javascript code or other malicious payloads.
The technical implementation of this vulnerability allows remote attackers to bypass the intended security controls by manipulating the file upload mechanism. When PhotoPost PHP processes uploaded files, it performs only basic extension validation without conducting thorough content analysis or magic number verification that would confirm the actual file type. This incomplete verification process creates a pathway for attackers to upload files that appear to be legitimate images but contain executable code. The vulnerability specifically targets the image handling functionality within the application, where uploaded files are typically stored and subsequently displayed to other users, creating a cross-site scripting attack vector.
The operational impact of this vulnerability is significant as it enables persistent cross-site scripting attacks that can compromise user sessions and potentially lead to complete system compromise. When victims view the maliciously uploaded images, the embedded javascript code executes within their browser context, potentially stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of authenticated users. This vulnerability affects the integrity and confidentiality of the application's user data and can be leveraged for privilege escalation attacks. The attack surface expands to include all users who view the compromised images, making this a widespread threat that can affect the entire user base.
Mitigation strategies for this vulnerability should focus on implementing robust file validation mechanisms that go beyond simple extension checking. Organizations should deploy comprehensive file type verification using multiple approaches including magic number detection, content analysis, and MIME type validation. The solution must include proper file content inspection that examines the actual binary structure of uploaded files rather than relying on potentially manipulated file extensions. Additionally, implementing proper file storage practices such as storing uploaded files outside the web root directory and using randomized filenames can significantly reduce the attack surface. This vulnerability aligns with ATT&CK technique T1505.003 for "Upload Malicious File" and demonstrates the importance of adhering to secure coding practices as outlined in OWASP Top 10 A04:2021 - "Insecure Design" and the principle of least privilege in file handling operations.