CVE-2018-18259 in LUYA
Summary
by MITRE
Stored XSS has been discovered in version 1.0.12 of the LUYA CMS software via /admin/api-cms-nav/create-page.
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Analysis
by VulDB Data Team • 05/25/2023
The vulnerability CVE-2018-18259 represents a stored cross-site scripting flaw within the LUYA CMS software version 1.0.12, specifically affecting the /admin/api-cms-nav/create-page endpoint. This issue arises from insufficient input validation and output sanitization mechanisms within the content management system's administrative interface, creating a persistent security weakness that allows attackers to inject malicious scripts into the application's database. The vulnerability exists in the page creation API endpoint where user-supplied data is not properly sanitized before being stored and subsequently rendered back to authenticated users, making it a classic example of a stored XSS vulnerability that can be exploited across multiple sessions.
The technical implementation of this vulnerability stems from the application's failure to properly validate and sanitize user input parameters when creating new navigation pages through the administrative API. When administrators or users with appropriate privileges submit page data through the /admin/api-cms-nav/create-page endpoint, the system stores this data without adequate filtering of potentially malicious content. The stored data is later retrieved and displayed in the user interface without proper HTML escaping or content sanitization, allowing attackers to inject JavaScript code that executes in the context of other users' browsers. This flaw operates at the intersection of CWE-79 and CWE-80, representing both a failure to sanitize input and a failure to properly escape output, creating an environment where malicious scripts can persist and propagate.
The operational impact of CVE-2018-18259 extends beyond simple data theft or defacement, as it can enable attackers to escalate privileges and gain unauthorized access to administrative functions. An attacker who successfully exploits this vulnerability can execute arbitrary JavaScript code in the browser of authenticated users, potentially stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of the victims. The stored nature of the vulnerability means that the malicious payload persists even after the initial injection, making it particularly dangerous as it can affect multiple users over time. This vulnerability aligns with ATT&CK technique T1531, which describes the use of malicious files or scripts to gain access to systems, and can be leveraged to establish persistent access to the CMS environment.
Mitigation strategies for CVE-2018-18259 should focus on implementing comprehensive input validation and output sanitization measures throughout the application. Organizations should immediately upgrade to a patched version of LUYA CMS where the vulnerability has been addressed through proper parameter validation and sanitization of user inputs. The implementation of Content Security Policy headers can provide additional defense-in-depth measures to limit the execution of unauthorized scripts. Security measures should include validating all user-supplied data against whitelisted character sets, implementing proper HTML escaping for all dynamic content, and conducting regular security testing to identify similar vulnerabilities in other API endpoints. Additionally, organizations should implement proper access controls and monitoring to detect unauthorized modifications to CMS content, as the vulnerability can be exploited by both external attackers and compromised internal users. The fix typically involves ensuring that all input parameters are properly validated and that any stored data is sanitized before being rendered in the user interface, addressing the root cause identified in CWE-79 and CWE-80 categories.