CVE-2017-11581 in FineCMS
Summary
by MITRE
dayrui FineCms 5.0.9 has Cross Site Scripting (XSS) in admin/Login.php via a payload in the username field that does not begin with a '<' character.
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Analysis
by VulDB Data Team • 12/29/2019
The vulnerability identified as CVE-2017-11581 affects dayrui FineCms version 5.0.9 and represents a cross site scripting flaw in the administrative login component. This issue manifests when processing user input through the username field in the admin/Login.php script, creating a potential attack vector that could be exploited by malicious actors to execute arbitrary code within the context of a victim's browser session. The vulnerability is particularly concerning as it targets the administrative interface, which typically holds elevated privileges and access to sensitive system functions. The specific condition that triggers this vulnerability requires the payload in the username field to not begin with a '<' character, suggesting that the application performs some form of input validation or sanitization that may be bypassed under certain circumstances.
From a technical perspective, this XSS vulnerability stems from insufficient input validation and output encoding within the administrative login form processing logic. The application fails to properly sanitize user-supplied data before incorporating it into dynamic web page content, allowing malicious script code to be injected and subsequently executed when the page is rendered. The restriction that payloads must not begin with '<' characters indicates that the system may be performing basic filtering or validation that could be circumvented through creative input manipulation, potentially exploiting weaknesses in the validation logic itself. This type of vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting vulnerabilities in software applications, particularly those involving improper neutralization of input during web page generation.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with potential access to administrative functions and sensitive system information. Successful exploitation could enable attackers to hijack administrator sessions, gain unauthorized access to system configurations, modify content, or potentially escalate privileges within the application environment. The vulnerability's presence in the login component means that attackers could potentially leverage this flaw to establish persistent access to the administrative interface, making it particularly dangerous for organizations relying on this content management system for critical operations. Attackers could craft malicious payloads that, when submitted through the login form, would execute in the context of authenticated administrator sessions, potentially leading to complete system compromise.
Mitigation strategies for this vulnerability should include implementing comprehensive input validation and output encoding practices throughout the application's codebase, particularly in areas handling user-supplied data. The application should employ strict sanitization of all input fields, including the username field in login forms, to prevent script injection attempts regardless of input format or character sequences. Organizations should also implement proper Content Security Policy headers to limit script execution capabilities and reduce the impact of successful XSS attacks. Regular security assessments and code reviews should be conducted to identify and remediate similar vulnerabilities in other application components. The fix should address the underlying validation logic to ensure that all user input is properly escaped or encoded before being processed or displayed, aligning with security best practices recommended by organizations such as the Open Web Application Security Project and following the ATT&CK framework's approach to identifying and mitigating web application vulnerabilities. Additionally, implementing proper session management and authentication controls would further reduce the risk of exploitation and limit the potential damage from successful attacks.