CVE-2017-16841 in Lansweeper
Summary
by MITRE
LanSweeper 6.0.100.75 has XSS via the description parameter to /Calendar/CalendarActions.aspx.
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Analysis
by VulDB Data Team • 06/18/2024
The vulnerability identified as CVE-2017-16841 affects LanSweeper version 6.0.100.75 and represents a cross-site scripting flaw that resides within the calendar functionality of the application. This issue manifests when the application fails to properly sanitize user input submitted through the description parameter to the CalendarActions.aspx page. The vulnerability classification aligns with CWE-79 which specifically addresses Cross-Site Scripting vulnerabilities where untrusted data is incorporated into web pages without proper validation or encoding. The flaw exists in the application's input handling mechanism, where the description field lacks adequate sanitization before being rendered back to users within the calendar interface.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input containing script code within the description parameter and submits it through the CalendarActions.aspx endpoint. When other users view the calendar entries containing this malicious input, the embedded scripts execute in their browsers within the context of the vulnerable application. This creates a persistent XSS vector that can be leveraged for session hijacking, credential theft, or redirection to malicious sites. The vulnerability demonstrates a classic reflected XSS pattern where user-supplied data flows directly into the application's output without appropriate context-aware encoding or validation. The attack requires no special privileges and can be executed through simple web requests, making it particularly dangerous in environments where multiple users interact with the calendar system.
The operational impact of this vulnerability extends beyond simple script execution as it can be weaponized to perform sophisticated attacks against the LanSweeper environment. Attackers can leverage this flaw to steal user sessions, modify calendar entries to spread malicious payloads, or redirect victims to phishing sites that appear legitimate within the application context. The persistent nature of calendar entries means that once a malicious script is injected, it can affect all users who view the affected calendar data. This vulnerability undermines the security posture of the entire LanSweeper deployment and can serve as a foothold for further attacks within the network. Organizations using this version of LanSweeper face potential data exposure and unauthorized access risks, particularly in environments where sensitive network information is stored within calendar entries.
Mitigation strategies for this vulnerability should include immediate implementation of proper input validation and output encoding mechanisms within the application code. The recommended approach involves sanitizing all user input through established encoding libraries that escape special characters before rendering data in web contexts. Organizations should also implement Content Security Policy headers to limit script execution capabilities and prevent unauthorized code injection. Regular security updates and patches should be applied immediately upon availability, as this vulnerability affects a specific version of the software that likely contains additional unpatched flaws. System administrators should conduct comprehensive security assessments of the LanSweeper installation to identify other potential input vectors that may exhibit similar vulnerabilities. The remediation process should also include user education regarding the dangers of clicking on untrusted calendar entries and implementing proper access controls to limit who can submit calendar entries. This vulnerability demonstrates the critical importance of input validation in web applications and aligns with ATT&CK technique T1211 which covers exploitation of vulnerabilities for privilege escalation and persistent access.