CVE-2019-9142 in Symphony
Summary
by MITRE
An issue was discovered in b3log Symphony (aka Sym) before v3.4.7. XSS exists via the userIntro and userNickname fields to processor/SettingsProcessor.java.
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Analysis
by VulDB Data Team • 07/19/2023
The vulnerability identified as CVE-2019-9142 affects the b3log Symphony application, specifically versions prior to v3.4.7, and represents a cross-site scripting vulnerability that could enable attackers to execute malicious scripts in the context of a victim's browser. This flaw resides within the processor/SettingsProcessor.java component of the application, making it a server-side processing issue that directly impacts user input handling and validation mechanisms. The vulnerability specifically targets the userIntro and userNickname fields, which are typically used for user profile customization and personal information display within the application's settings interface.
The technical nature of this vulnerability stems from insufficient input sanitization and output encoding within the SettingsProcessor.java file. When users submit data through the userIntro and userNickname fields, the application fails to properly validate or sanitize this input before storing or rendering it back to users. This allows malicious actors to inject crafted script code that executes in the browser context of other users who view the affected profile information. The vulnerability classifies under CWE-79, which specifically addresses Cross-Site Scripting flaws, and represents a classic case of unsafe output encoding where user-controllable data is directly included in web responses without proper sanitization. The attack vector is particularly concerning as it leverages the application's legitimate user profile management functionality to deliver malicious payloads.
The operational impact of this vulnerability extends beyond simple script execution, as it could enable attackers to perform session hijacking, steal sensitive user information, manipulate application data, or redirect users to malicious websites. Attackers could craft malicious payloads within the userIntro field that would execute whenever other users view the affected profiles, potentially compromising multiple user sessions and leading to unauthorized access to sensitive application data. The vulnerability's persistence in the application's user profile system means that the malicious code could remain active for extended periods, continuously affecting any user who encounters the compromised profile information. This type of vulnerability also aligns with ATT&CK technique T1566, which covers social engineering through spearphishing with malicious attachments or links, as the XSS could be used to deliver additional malicious payloads or redirect users to phishing sites.
Mitigation strategies for CVE-2019-9142 should focus on implementing proper input validation and output encoding mechanisms within the SettingsProcessor.java component. The most effective immediate solution involves upgrading to Symphony version 3.4.7 or later, where the vulnerability has been patched. Organizations should also implement comprehensive input sanitization that strips or encodes potentially dangerous characters from user inputs before processing. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting script execution within the application's context. Regular security testing and code reviews should be conducted to identify similar vulnerabilities in other input handling components, particularly those that process user-generated content for display in web interfaces. The remediation process should also include validating all user profile fields against a whitelist of safe characters and implementing proper HTML escaping for all dynamic content rendered in web responses to prevent similar vulnerabilities from emerging in other parts of the application.