CVE-2019-12927 in Enterprise Premium
Summary
by MITRE
MailEnable Enterprise Premium 10.23 was vulnerable to stored and reflected cross-site scripting (XSS) attacks. Because the session cookie did not use the HttpOnly flag, it was possible to hijack the session cookie by exploiting this vulnerability.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/02/2020
The vulnerability identified as CVE-2019-12927 affects MailEnable Enterprise Premium version 10.23 and represents a critical security flaw that enables both stored and reflected cross-site scripting attacks. This vulnerability resides within the web application interface of the mail server software, creating an exploitable entry point for malicious actors to inject malicious scripts into web pages viewed by other users. The flaw allows attackers to execute arbitrary JavaScript code in the context of a victim's browser session, potentially leading to complete compromise of user accounts and unauthorized access to sensitive email communications.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within the MailEnable web interface components. When user-supplied data is not properly sanitized before being rendered in web pages, it creates opportunities for attackers to inject malicious payloads that persist in the application's database or are reflected back in HTTP responses. The stored XSS component allows malicious scripts to be permanently stored within the application's data storage, executing whenever affected pages are accessed by other users. The reflected XSS variant enables attackers to craft malicious URLs that, when clicked by victims, execute scripts directly from the request parameters without permanent storage.
The security implications of this vulnerability extend beyond simple script execution, particularly due to the absence of the HttpOnly flag on session cookies. This critical configuration oversight means that JavaScript running in the victim's browser can access and extract session cookies through document.cookie properties. The combination of XSS exploitation and the missing HttpOnly flag creates a complete session hijacking scenario where attackers can steal authentication tokens and impersonate legitimate users. This vulnerability directly maps to CWE-79 which describes cross-site scripting flaws, and CWE-1004 which addresses insecure cookie attributes. The attack surface is further expanded through ATT&CK technique T1566 which covers social engineering via spearphishing with a link, making this vulnerability particularly dangerous in targeted attack scenarios.
The operational impact of CVE-2019-12927 is severe for organizations relying on MailEnable Enterprise Premium for their email infrastructure. Successful exploitation can result in unauthorized access to user email accounts, data exfiltration, message manipulation, and potential lateral movement within the network. Attackers can leverage stolen sessions to read sensitive communications, send emails on behalf of users, and access confidential business information. The vulnerability affects both administrative and regular user accounts, potentially providing attackers with elevated privileges when targeting administrator sessions. Organizations may experience significant reputational damage, regulatory compliance violations, and potential financial losses due to data breaches or service disruption. The vulnerability also enables persistent threats where attackers can maintain access through stored XSS payloads that execute whenever users access affected application components.
Mitigation strategies for CVE-2019-12927 require immediate action to address both the XSS vulnerabilities and the session cookie configuration issues. Organizations should apply the vendor-provided security patches or updates that correct the input validation and output encoding flaws in the MailEnable web interface. The session cookie configuration must be updated to include the HttpOnly flag, which prevents JavaScript access to session tokens and significantly reduces the attack surface for session hijacking. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting script execution sources. Network segmentation and monitoring solutions should be deployed to detect and alert on suspicious activities related to the affected MailEnable components. Regular security assessments and penetration testing should be conducted to verify that all XSS vulnerabilities have been properly addressed and that proper cookie security configurations are maintained. Organizations should also implement user education programs to reduce the risk of successful social engineering attacks that may exploit this vulnerability through phishing campaigns.