CVE-2016-1188 in Garoon
Summary
by MITRE
Cybozu Garoon 3.x and 4.x before 4.2.1 allows remote authenticated users to send spoofed e-mail messages via unspecified vectors.
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Analysis
by VulDB Data Team • 02/09/2019
The vulnerability identified as CVE-2016-1188 affects Cybozu Garoon versions 3.x and 4.x prior to 4.2.1, representing a significant security flaw in email handling mechanisms within the collaborative software platform. This issue specifically enables authenticated remote attackers to manipulate email spoofing capabilities, potentially compromising the integrity and authenticity of communications within organizational networks that rely on this system. The vulnerability stems from insufficient validation and sanitization of email headers and routing information during message processing, creating opportunities for malicious actors to exploit the system's trust mechanisms. The affected versions of Garoon operate as enterprise collaboration platforms that integrate email services with calendar management and document sharing functionalities, making this vulnerability particularly concerning for organizations relying on these integrated services for business operations.
The technical implementation of this vulnerability involves unspecified vectors that likely encompass improper handling of email message headers, sender address validation bypasses, or inadequate message routing controls within the Garoon email subsystem. Attackers with legitimate authentication credentials can leverage these weaknesses to craft and transmit forged email messages that appear to originate from authorized users or system components. This type of vulnerability aligns with CWE-20, which describes improper input validation, and may also relate to CWE-345, indicating insufficient verification of data integrity. The attack vector typically requires an authenticated user context, making it a privilege escalation or lateral movement vulnerability rather than a simple remote code execution flaw, though the implications for email security and trust are severe. The underlying mechanism likely involves manipulation of email envelope data or header fields that are not properly validated against legitimate source parameters.
The operational impact of CVE-2016-1188 extends beyond simple email spoofing, potentially enabling more sophisticated attacks such as phishing campaigns, social engineering operations, and trust-based privilege abuse within organizations using Garoon platforms. Security administrators may observe unusual email patterns, unauthorized message forwarding, or compromised user trust relationships as indicators of exploitation. Organizations relying on Garoon for business-critical communications could face reputation damage, compliance violations, and potential data breaches if attackers use this vulnerability to gain unauthorized access to sensitive information. The vulnerability particularly affects enterprise environments where email authentication and integrity are critical for maintaining security boundaries and protecting against insider threats. This flaw undermines the fundamental security assumptions of email systems, potentially allowing attackers to bypass security controls that depend on email authenticity and trust relationships established within the platform.
Mitigation strategies for CVE-2016-1188 should prioritize immediate patch deployment to upgrade affected Garoon installations to version 4.2.1 or later, which contains the necessary fixes for email validation and spoofing prevention mechanisms. Organizations should also implement additional email security controls including spam filtering, email authentication protocols such as SPF, DKIM, and DMARC, and monitoring systems to detect anomalous email patterns. Network segmentation and access controls should be reinforced to limit the scope of potential exploitation, particularly for users with elevated privileges. Security teams should conduct thorough vulnerability assessments of their email infrastructure and review existing email handling policies to ensure proper validation of message sources. The remediation process should include user education on recognizing spoofed emails and establishing incident response procedures for email-related security events. Organizations may also consider implementing email encryption and digital signatures to provide additional layers of authentication beyond what the patched system provides. This vulnerability highlights the importance of maintaining up-to-date security patches and the necessity of comprehensive email security architectures that protect against both external and internal threats.