CVE-2017-9668 in CMS Made Simple
Summary
by MITRE
In admin\addgroup.php in CMS Made Simple 2.1.6, when adding a user group, there is no XSS filtering, resulting in storage-type XSS generation, via the description parameter in an addgroup action.
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Analysis
by VulDB Data Team • 10/18/2019
The vulnerability identified as CVE-2017-9668 resides within the adminddgroup.php component of CMS Made Simple version 2.1.6, representing a critical security flaw that enables cross-site scripting attacks through improper input validation. This issue specifically manifests during the user group creation process where the description parameter fails to undergo adequate sanitization before being stored in the application's database. The absence of input filtering creates a persistent vulnerability that allows malicious actors to inject malicious scripts into the system's storage layer, which then executes whenever the stored content is rendered to authenticated users. This particular weakness falls under the category of stored cross-site scripting as defined by CWE-79, which occurs when user-supplied data is stored and later executed in the victim's browser without proper sanitization.
The technical exploitation of this vulnerability requires an attacker to navigate to the group management interface within the CMS admin panel and initiate the addgroup action while providing malicious script code within the description field. Once submitted, the vulnerable code becomes permanently stored in the database and will execute in the context of any user who views the group information, including administrators. The attack vector leverages the trust relationship between the web application and its users, as the malicious payload is delivered through legitimate administrative functionality rather than external injection. This vulnerability directly violates security principles outlined in the OWASP Top Ten 2017, specifically targeting the injection category that encompasses cross-site scripting flaws.
The operational impact of CVE-2017-9668 extends beyond simple script execution, as it provides attackers with potential access to sensitive administrative functions and user data. When executed in the context of an administrator's browser session, the stored XSS payload can perform actions such as stealing session cookies, modifying group permissions, accessing confidential user information, or redirecting users to malicious sites. The vulnerability's persistence makes it particularly dangerous as the malicious scripts remain active until manually removed from the database, potentially allowing attackers to maintain long-term access to compromised systems. This type of vulnerability also aligns with ATT&CK technique T1059.001 for command and scripting interpreter, as the stored scripts can be used to execute arbitrary commands or establish persistent access patterns.
Organizations utilizing CMS Made Simple 2.1.6 should immediately implement mitigations including comprehensive input sanitization for all user-supplied data, particularly within administrative interfaces. The recommended approach involves implementing proper HTML escaping and output encoding for all dynamic content rendered to users, while also applying strict validation rules to prevent script injection attempts. Additionally, implementing Content Security Policy (CSP) headers can provide an additional layer of protection against XSS attacks by restricting the sources from which scripts can be loaded. Regular security audits and input validation testing should be conducted to identify similar vulnerabilities within the application's codebase, as this flaw represents a common pattern in web application security that can affect numerous CMS platforms and custom applications. The vulnerability demonstrates the critical importance of sanitizing all user inputs in administrative functions and implementing defense-in-depth strategies to protect against persistent security flaws.