CVE-2018-16347 in Gleez
Summary
by MITRE
An issue was discovered in Gleez CMS v1.2.0. There is XSS via media/imagecache/resize.
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Analysis
by VulDB Data Team • 05/06/2023
The vulnerability identified as CVE-2018-16347 represents a cross-site scripting flaw within Gleez CMS version 1.2.0 that specifically affects the media/imagecache/resize functionality. This issue resides in the content management system's handling of image processing requests, where user-supplied input is not properly sanitized before being rendered in web responses. The vulnerability manifests when attackers can inject malicious scripts through image resize operations, potentially compromising user sessions and enabling unauthorized actions on behalf of victims. The affected component operates as part of the CMS's media management system, which processes image transformations for web display purposes, making it a critical attack vector for malicious actors seeking to exploit web applications.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the image cache resizing module. When users upload images or request specific image dimensions through the media/imagecache/resize endpoint, the application fails to properly escape or filter user-provided parameters before incorporating them into HTML responses. This allows attackers to inject malicious JavaScript code that executes in the context of other users' browsers when they view the affected images. The flaw operates under CWE-79 which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding, specifically targeting the improper handling of untrusted data within web applications. The vulnerability is particularly concerning as it can be exploited through simple HTTP requests without requiring authentication or privileged access.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform session hijacking, deface websites, steal sensitive information, or redirect users to malicious domains. An attacker could craft specially formatted image resize requests that include malicious payloads, which would then be executed whenever legitimate users view the affected content. This creates a persistent threat vector that remains active as long as the vulnerable CMS version is deployed. The attack surface is broadened by the fact that the vulnerability affects core media processing functionality, which is typically used by content creators and administrators, increasing the likelihood of exploitation. According to ATT&CK framework, this vulnerability maps to T1059.007 for script injection and T1531 for credential access, demonstrating how a single XSS flaw can enable multiple attack vectors within the broader threat landscape.
Mitigation strategies for CVE-2018-16347 should prioritize immediate patching of the Gleez CMS to a version that properly sanitizes input parameters in the image cache module. Organizations should implement strict input validation and output encoding practices specifically for the media/imagecache/resize endpoint, ensuring all user-supplied data is properly escaped before inclusion in web responses. Network-based protections such as web application firewalls can provide additional layers of defense by monitoring for suspicious patterns in image processing requests. Security teams should also conduct comprehensive audits of all CMS modules and third-party plugins to identify similar input validation weaknesses. Regular security assessments and penetration testing should be performed to ensure that image processing and media handling components are properly secured. The vulnerability underscores the importance of implementing defense-in-depth strategies where multiple security controls work together to prevent exploitation of input validation flaws in web applications.