CVE-2021-43696 in twmap
Summary
by MITRE • 11/29/2021
An unspecified version of twmap is affected by a Cross Site Scripting (XSS) vulnerability. In file list.php, the exit function will terminate the script and print the message to the user. The message will contain $_REQUEST then there is a XSS vulnerability.
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Analysis
by VulDB Data Team • 12/02/2021
The vulnerability identified as CVE-2021-43696 affects the twmap application, specifically targeting a cross site scripting flaw within the list.php file. This vulnerability stems from improper input validation and output encoding practices that allow malicious actors to inject malicious scripts into the application's response. The flaw occurs when the exit function terminates script execution and displays user-supplied data directly to the browser without adequate sanitization or encoding. The $_REQUEST superglobal variable contains parameters that are passed through the HTTP request and are subsequently printed to the user interface without proper security measures. This represents a classic XSS vulnerability that falls under CWE-79, which specifically addresses cross site scripting flaws in web applications.
The technical implementation of this vulnerability demonstrates a dangerous pattern where user-controllable input flows directly into the application's output stream without proper sanitization. When the exit function is invoked, it processes the $_REQUEST data and displays it to the end user, creating an opportunity for attackers to inject malicious JavaScript code. The vulnerability is particularly concerning because it can be exploited through various request methods including GET and POST parameters, allowing attackers to craft malicious URLs or forms that will execute arbitrary code in the context of a victim's browser session. This type of vulnerability enables attackers to perform session hijacking, defacement of web pages, or redirection to malicious sites, all while appearing to originate from a legitimate source within the trusted application.
The operational impact of this vulnerability extends beyond simple data theft or defacement. Attackers can leverage this XSS flaw to establish persistent malicious presence within the application environment, potentially compromising user sessions and accessing sensitive data that should remain protected. The vulnerability affects the integrity and confidentiality of the web application, as users may unknowingly execute malicious payloads that could lead to complete compromise of their browser sessions. This type of vulnerability is particularly dangerous in environments where users may have elevated privileges or access to sensitive information, as the attacker could potentially escalate privileges or gain unauthorized access to protected resources. The attack surface is broad since the vulnerability exists in a file that likely handles user list operations, meaning any user interaction with this functionality could be exploited.
Mitigation strategies for CVE-2021-43696 should focus on implementing proper input validation and output encoding mechanisms throughout the application. The recommended approach involves sanitizing all user-supplied input before it is processed or displayed, utilizing proper HTML encoding functions such as htmlspecialchars() or equivalent security measures. The application should implement Content Security Policy headers to prevent execution of unauthorized scripts, while also ensuring that all user-controllable parameters are properly validated against expected input formats. Additionally, developers should adopt secure coding practices that follow the principle of least privilege, ensuring that any error messages or system responses do not inadvertently expose sensitive information. This vulnerability aligns with ATT&CK technique T1059.007 for script injection and T1566 for credential harvesting, making it a critical target for immediate remediation. The fix should involve comprehensive input sanitization and output encoding, with thorough testing to ensure that no similar vulnerabilities exist in other parts of the application codebase.