CVE-2018-0557 in Mailwise
Summary
by MITRE
Stored cross-site scripting vulnerability in Cybozu Mailwise 5.0.0 to 5.4.1 allows remote attackers to inject arbitrary web script or HTML 'E-mail Details Screen' via unspecified vectors.
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Analysis
by VulDB Data Team • 02/21/2020
The stored cross-site scripting vulnerability identified as CVE-2018-0557 affects Cybozu Mailwise versions 5.0.0 through 5.4.1, representing a critical security flaw that enables remote attackers to execute malicious web scripts within the context of affected systems. This vulnerability specifically targets the email details screen functionality, creating an attack surface where malicious input can be persistently stored and subsequently executed when users view the compromised email content. The flaw stems from inadequate input validation and output encoding mechanisms within the application's web interface, allowing attackers to inject malicious code that becomes permanently stored within the system's email database.
The technical implementation of this vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws as weaknesses in web applications where untrusted data is improperly sanitized before being rendered to users. Attackers can exploit this weakness by crafting specially formatted email messages containing malicious javascript payloads or html code that gets stored in the Mailwise system. When legitimate users navigate to the email details screen to view the compromised message, the stored malicious code executes in their browser context, potentially leading to session hijacking, credential theft, or further exploitation of the victim's system. The persistent nature of stored XSS makes this vulnerability particularly dangerous as the malicious code remains active until manually removed from the system.
The operational impact of CVE-2018-0557 extends beyond simple data theft, as it provides attackers with a foothold for more sophisticated attacks within the organization's email infrastructure. This vulnerability can be leveraged for privilege escalation attacks, where attackers might gain access to sensitive email communications, calendar data, or contact information stored within the Mailwise system. The attack vector operates through the email details screen functionality, meaning that any user who views the compromised email content becomes a potential victim, making this vulnerability particularly effective for mass deployment attacks. Organizations using Mailwise versions within the affected range face significant risk of unauthorized access and data compromise, especially in environments where email serves as a primary communication channel for business operations.
Mitigation strategies for CVE-2018-0557 should prioritize immediate patching of affected Mailwise installations to the latest available versions that contain proper input validation and output encoding fixes. Organizations should implement comprehensive web application firewalls that can detect and block malicious script injection attempts, while also establishing strict email content filtering policies to prevent the delivery of suspicious email attachments or links. Security teams should conduct regular vulnerability assessments of their email infrastructure and implement proper input sanitization controls that validate and escape all user-supplied data before it is stored or rendered. Additionally, user education programs should emphasize the importance of not clicking on suspicious links or downloading attachments from unknown sources, as these measures can significantly reduce the impact of successful XSS exploitation attempts. The remediation process should also include thorough audit of existing email content to identify any previously stored malicious payloads that may have been injected prior to patching, ensuring complete system restoration and preventing potential long-term security compromise.