CVE-2017-2256 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 "Rich text" funtion of the application "Memo".
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Analysis
by VulDB Data Team • 11/11/2019
The vulnerability identified as CVE-2017-2256 represents a critical cross-site scripting flaw within Cybozu Garoon versions 3.0.0 through 4.2.5. This weakness specifically targets the rich text functionality of the Memo application component, creating a pathway for malicious actors to execute arbitrary web scripts and HTML code within the context of affected user sessions. The vulnerability stems from insufficient input validation and output encoding mechanisms that fail to properly sanitize user-supplied content before rendering it within the application's web interface.
The technical exploitation of this vulnerability occurs through the manipulation of the rich text editor's input handling mechanisms. When users create or edit memo entries containing malicious script code within the rich text fields, the application fails to adequately filter or escape special characters that could be interpreted as executable code by web browsers. This allows attackers to inject malicious payloads that persist in the application's database and execute whenever other users view the affected memo entries. The vulnerability is classified under CWE-79 as Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly encode or escape user-controllable data before including it in dynamically generated web content.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform a wide range of malicious activities including session hijacking, credential theft, and data exfiltration. An attacker who successfully exploits this vulnerability can potentially establish persistent access to the application environment, manipulate user sessions, and gain unauthorized access to sensitive organizational information stored within the Garoon platform. The affected environment typically includes corporate collaboration systems where users frequently exchange memos and notes, making this vulnerability particularly dangerous in enterprise settings where sensitive business information is regularly shared.
The attack vector for this vulnerability requires minimal privileges and can be executed through simple web interface interactions. Attackers need only create a malicious memo entry containing crafted script payloads, which can be delivered via various methods including social engineering or compromised user accounts. The vulnerability affects all versions within the specified range, indicating a widespread exposure across organizations utilizing these Cybozu Garoon versions. Organizations should consider implementing the mitigations recommended by the vendor, including applying the latest security patches, implementing strict input validation controls, and deploying web application firewalls to detect and prevent malicious script injection attempts.
Security practitioners should also consider this vulnerability in the context of broader attack frameworks, particularly those targeting web application vulnerabilities as outlined in the MITRE ATT&CK framework under the technique T1059.007 for Command and Scripting Interpreter: JavaScript. The vulnerability represents a classic example of how rich text editors can become attack surfaces when proper sanitization mechanisms are not implemented, and it underscores the importance of defense-in-depth strategies that include both server-side input validation and client-side content filtering to prevent successful exploitation of similar vulnerabilities in collaborative software environments.