CVE-2017-2257 in Garoon
Summary
by MITRE
Cross-site scripting vulnerability in Cybozu Garoon 3.0.0 to 4.2.5 allows an attacker to inject arbitrary web script or HTML via mail function.
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Analysis
by VulDB Data Team • 11/11/2019
The vulnerability identified as CVE-2017-2257 represents a critical cross-site scripting flaw within Cybozu Garoon versions 3.0.0 through 4.2.5, specifically affecting the mail function component of this enterprise collaboration platform. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is a pervasive issue in web applications where user-supplied data is improperly sanitized before being rendered in web pages. The affected mail function in Garoon allows attackers to inject malicious scripts or HTML content that can be executed in the context of other users' browsers when they view the compromised email messages.
The technical exploitation of this vulnerability occurs through the manipulation of input fields within the mail function, where user-provided content is not adequately filtered or escaped before being stored and subsequently displayed to other users. Attackers can craft malicious payloads that, when processed by the vulnerable Garoon system, get embedded in email messages and executed in the browsers of unsuspecting recipients. This creates a persistent threat vector where malicious scripts can perform actions such as stealing session cookies, redirecting users to malicious sites, or executing unauthorized commands on behalf of the victim user. The vulnerability demonstrates a classic failure in input validation and output encoding practices, where the application fails to properly sanitize user-supplied data that flows into the HTML context of the web interface.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to establish persistent access to corporate networks through session hijacking and credential theft. When users with elevated privileges receive malicious emails, the potential for privilege escalation increases significantly, as the injected scripts can access sensitive corporate data and system functions. The attack surface is particularly concerning in enterprise environments where Garoon serves as a central collaboration platform, as a single compromised user account can provide attackers with access to a broader network of users and shared resources. This vulnerability aligns with ATT&CK technique T1566.001 for initial access through spearphishing attachments and T1071.004 for application layer protocol usage, making it a significant vector for advanced persistent threats targeting corporate infrastructure.
Organizations should implement multiple layers of mitigation to address this vulnerability, beginning with immediate patching of all affected Garoon versions to the latest secure releases that include proper input sanitization and output encoding mechanisms. Network segmentation and web application firewalls should be configured to monitor and filter suspicious content in email traffic, while security awareness training programs should educate users about identifying potentially malicious email content. The implementation of Content Security Policy headers and proper input validation frameworks can provide additional protection against similar vulnerabilities in other components of the system. Regular security assessments and code reviews focusing on input handling and output encoding practices should be conducted to prevent similar issues from emerging in future development cycles. Organizations should also consider implementing email scanning solutions that can detect and quarantine malicious payloads before they reach end users, while establishing robust incident response procedures to quickly address any successful exploitation attempts.