CVE-2015-5646 in Garoon
Summary
by MITRE
Cybozu Garoon 3.x through 3.7.5 and 4.x through 4.0.3 allows remote authenticated users to execute arbitrary PHP code via unspecified vectors, aka CyVDB-863 and CyVDB-867.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/31/2018
The vulnerability identified as CVE-2015-5646 represents a critical remote code execution flaw affecting Cybozu Garoon versions 3.x through 3.7.5 and 4.x through 4.0.3. This security issue enables authenticated attackers to execute arbitrary PHP code on the affected systems, potentially leading to complete system compromise. The vulnerability was catalogued under CyVDB-863 and CyVDB-867, indicating its significance within the Cybozu security advisory framework. The flaw exists in the application's handling of user input within unspecified vectors, creating an avenue for malicious code injection that bypasses normal authentication mechanisms.
The technical nature of this vulnerability stems from improper input validation and sanitization within the Garoon application's processing logic. Attackers with valid credentials can exploit this weakness to inject malicious PHP code that executes with the privileges of the web application. This type of vulnerability aligns with CWE-94, which describes improper control of generation of code, and falls under the ATT&CK technique T1059.007 for Command and Scripting Interpreter. The authenticated nature of the exploit means that attackers must first establish legitimate user sessions, but once inside the system, they can leverage this vulnerability to escalate their privileges and gain persistent access to the underlying infrastructure.
The operational impact of CVE-2015-5646 is severe and multifaceted, potentially allowing attackers to establish backdoors, exfiltrate sensitive data, modify system configurations, or deploy additional malware. Organizations using affected Garoon versions face significant risk of data breaches and system compromise, particularly in environments where the application handles confidential business information or serves as a central collaboration platform. The vulnerability's remote execution capability means that attackers can exploit it from anywhere with network access and valid credentials, making it particularly dangerous in cloud or distributed environments where authentication may be less strictly enforced.
Mitigation strategies for this vulnerability require immediate patching of affected systems to the latest supported versions of Cybozu Garoon. Organizations should implement network segmentation to limit access to the affected application and enforce strict access controls for user accounts. Security monitoring should be enhanced to detect unusual PHP code execution patterns or unauthorized file uploads that might indicate exploitation attempts. Additionally, implementing web application firewalls and input validation controls can provide additional defense layers. Organizations should also conduct thorough security assessments of their collaboration platforms and establish incident response procedures specifically addressing remote code execution vulnerabilities. The remediation process should include comprehensive testing of patches in staging environments before deployment to production systems to ensure operational stability while addressing the security threat.