CVE-2018-20369 in Message Archiver
Summary
by MITRE
Barracuda Message Archiver 2018 has XSS in the error_msg exception-handling value for the ldap_user parameter to the cgi-mod/ldap_load_entry.cgi module. The injection point of the issue is the Add_Update module.
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Analysis
by VulDB Data Team • 04/23/2020
The vulnerability identified as CVE-2018-20369 represents a cross-site scripting flaw within the Barracuda Message Archiver 2018 software system. This security weakness specifically manifests in the error message handling mechanism when processing the ldap_user parameter through the cgi-mod/ldap_load_entry.cgi module. The vulnerability occurs within the Add_Update module where exception handling fails to properly sanitize user input, creating an exploitable condition that allows malicious actors to inject arbitrary script code into the application's response. The flaw exists at the intersection of input validation and output encoding, where the system fails to adequately filter or escape special characters in the ldap_user parameter before incorporating it into error messages displayed to users.
The technical nature of this vulnerability places it squarely within the category of reflected cross-site scripting as defined by CWE-79, which occurs when a web application includes untrusted data in a new web page without proper validation or escaping. The attack vector specifically targets the ldap_user parameter, which suggests this vulnerability may be exploited through LDAP authentication or user management functions within the archiver system. When an attacker crafts a malicious payload containing script code within the ldap_user parameter and submits it through the ldap_load_entry.cgi interface, the system processes this input during error handling and subsequently reflects the malicious code back to the user's browser. This creates an environment where the injected script executes in the context of the victim's browser session, potentially enabling session hijacking, credential theft, or other malicious activities.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with a potential foothold for more sophisticated attacks within the email archiving infrastructure. Given that the Barracuda Message Archiver handles sensitive email communications and user authentication data, successful exploitation could allow threat actors to gain unauthorized access to archived messages, user credentials, or system configuration information. The vulnerability's presence in the exception handling mechanism suggests that it may be triggered during legitimate authentication failures or user management operations, making it particularly insidious as it can be exploited during normal system operation. This type of vulnerability also aligns with ATT&CK technique T1212, which involves exploitation of system information discovery mechanisms, as the compromised system could reveal information about the internal email infrastructure and user base.
Mitigation strategies for CVE-2018-20369 should focus on implementing robust input validation and output encoding measures throughout the application's parameter handling processes. Organizations should ensure that all user-supplied input, particularly parameters used in error handling and logging functions, undergoes proper sanitization before being incorporated into any output. The implementation of a comprehensive web application firewall or input validation layer can provide additional protection against similar injection attacks. System administrators should also consider applying the vendor-provided security patches or updates that address this specific vulnerability, as Barracuda would have likely released remediation measures to fix the insufficient input validation in the ldap_load_entry.cgi module. Regular security testing and code review processes should be implemented to identify similar vulnerabilities in other modules, particularly those handling user input during error conditions or system exception handling processes.