CVE-2016-4871 in Cybozu Office
Summary
by MITRE
Cybozu Office 9.0.0 through 10.4.0 allows remote attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 08/31/2020
Cybozu Office represents a suite of collaborative software applications used by organizations for document management and office automation tasks. The vulnerability identified as CVE-2016-4871 affects versions 9.0.0 through 10.4.0 of this software, creating a remote denial of service condition that can be exploited by attackers without requiring authentication or privileged access. This flaw exists within the application's processing mechanisms for specific file formats or network communications, allowing malicious actors to disrupt normal service operations. The vulnerability demonstrates characteristics consistent with CWE-119 which describes weaknesses in memory handling that can lead to system instability. Attackers can leverage this vulnerability to crash application processes or render the software unavailable to legitimate users, effectively creating a denial of service condition that impacts business continuity and productivity. The remote nature of this attack vector means that adversaries can exploit the vulnerability from outside the organization's network, making it particularly dangerous for enterprises that rely on Cybozu Office for critical business operations.
The technical implementation of this vulnerability involves a flaw in how the software handles certain input data or processing sequences that can trigger unexpected behavior in the application's runtime environment. This typically occurs when the software fails to properly validate or sanitize inputs received from network sources or file uploads, leading to memory corruption or resource exhaustion conditions. The exploitation process likely involves sending specially crafted data to the vulnerable application that causes it to malfunction or terminate unexpectedly. This type of vulnerability falls under the broader category of remote code execution risks that have been documented in similar office automation software platforms. The impact extends beyond simple service disruption as organizations may experience complete loss of access to collaborative features, document sharing capabilities, and workflow automation processes that depend on the affected software. From a cybersecurity perspective, this vulnerability represents a significant risk to enterprise environments where Cybozu Office is deployed across multiple departments and user groups.
Organizations utilizing affected versions of Cybozu Office should immediately implement mitigation strategies to protect their systems from exploitation attempts. The most effective approach involves applying the vendor-provided security patches and updates that address the specific denial of service vulnerability. Network segmentation and access controls should be implemented to limit exposure of the vulnerable software to untrusted networks and users. Monitoring systems should be configured to detect unusual network traffic patterns or service disruptions that may indicate exploitation attempts. Security teams should establish incident response procedures that include rapid identification and containment of potential exploitation activities. The vulnerability also highlights the importance of maintaining up-to-date software inventory records and implementing regular vulnerability assessments to identify similar weaknesses in other enterprise applications. Organizations should consider implementing network-based intrusion detection systems that can identify and alert on known attack patterns targeting this specific vulnerability. From an att&ck framework perspective, this vulnerability maps to techniques involving service stoppage and system availability disruption, which are commonly used in ransomware and advanced persistent threat campaigns targeting enterprise infrastructure. The remediation process should include thorough testing of patches in controlled environments before deployment to production systems to ensure that security updates do not introduce compatibility issues with existing business processes.