CVE-2020-5564 in Garoon
Summary
by MITRE
Cross-site scripting vulnerability in Cybozu Garoon 4.0.0 to 4.10.3 allows remote attackers to inject arbitrary web script or HTML via the application 'E-mail'.
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Analysis
by VulDB Data Team • 06/03/2024
The vulnerability identified as CVE-2020-5564 represents a critical cross-site scripting flaw within Cybozu Garoon versions 4.0.0 through 4.10.3. This security weakness specifically manifests within the application's email handling functionality, creating an avenue for remote attackers to execute malicious code within the context of affected user sessions. The vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is classified as a fundamental web application security flaw that enables attackers to inject client-side scripts into web pages viewed by other users. The impact of this vulnerability extends beyond simple script execution, as it can potentially lead to session hijacking, data theft, and unauthorized access to sensitive corporate information.
The technical exploitation of this vulnerability occurs through the email application component of Garoon, where input validation mechanisms fail to properly sanitize user-supplied data. When users receive or interact with specially crafted email messages containing malicious scripts, the application fails to adequately filter or escape the input before rendering it in the web interface. This allows attackers to inject HTML tags, javascript code, or other malicious content that executes in the context of the victim's browser session. The vulnerability is particularly concerning because email is a primary communication channel in enterprise environments, making it an attractive target for attackers seeking to compromise multiple users simultaneously. The flaw operates at the application layer and requires no special privileges to exploit, making it accessible to any remote attacker with knowledge of the target system.
The operational impact of CVE-2020-5564 is significant for organizations utilizing Cybozu Garoon, as it creates potential pathways for widespread security breaches within corporate networks. Attackers could leverage this vulnerability to steal user credentials, access confidential business communications, or establish persistent access points within the organization's infrastructure. The attack surface is broad since email is a fundamental component of most business operations, and the vulnerability affects multiple versions of the software, increasing the potential attack vector. Organizations may experience data loss, regulatory compliance violations, and reputational damage if this vulnerability is exploited successfully. The vulnerability also aligns with ATT&CK technique T1566 which involves social engineering through email, and T1071.004 which covers application layer protocol usage for command and control communications.
Mitigation strategies for this vulnerability should include immediate application of vendor patches and updates to the latest available versions of Cybozu Garoon that address the XSS flaw. Organizations should implement robust input validation and output encoding mechanisms within their email handling systems to prevent malicious script injection. Network segmentation and web application firewalls can provide additional layers of protection by monitoring and filtering suspicious traffic patterns. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities within the email infrastructure. Security awareness training for end users remains crucial in preventing successful exploitation, as attackers often rely on social engineering tactics to deliver malicious payloads through email. Additionally, implementing content security policies and disabling unnecessary email features can reduce the attack surface and limit the potential impact of any successful exploitation attempts.