CVE-2015-8483 in Office
Summary
by MITRE
Open redirect vulnerability in Cybozu Office 10.2.0 through 10.3.0 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a crafted URL.
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Analysis
by VulDB Data Team • 07/30/2018
The vulnerability identified as CVE-2015-8483 represents a critical open redirect flaw discovered in Cybozu Office versions 10.2.0 through 10.3.0. This security weakness enables remote attackers to manipulate user navigation by constructing malicious URLs that redirect victims to arbitrary websites without proper validation. The vulnerability operates by failing to adequately sanitize user input in redirect parameters, allowing attackers to craft URLs that appear legitimate but ultimately direct users to malicious destinations.
This open redirect vulnerability falls under the Common Weakness Enumeration category CWE-601, which specifically addresses URL redirect vulnerabilities where applications redirect users to external sites without proper validation. The flaw creates a significant attack surface that can be exploited by threat actors to execute phishing campaigns, steal user credentials, or distribute malware. The vulnerability exists in the application's handling of redirect parameters, where user-supplied input is not properly validated or sanitized before being used to construct redirect URLs.
The operational impact of CVE-2015-8483 extends beyond simple redirection, as it provides attackers with a mechanism to conduct sophisticated social engineering attacks. When users encounter a maliciously crafted URL, they may be tricked into believing they are navigating to a legitimate Cybozu Office site while actually being redirected to phishing pages that mimic the genuine interface. This creates a dangerous environment where user trust is exploited to gain unauthorized access to sensitive information, particularly when users are unaware of the redirection occurring. The vulnerability affects all versions within the specified range, indicating a widespread exposure across multiple deployments of the software.
The attack vector for this vulnerability requires minimal technical expertise and can be executed through simple URL manipulation techniques. Attackers can construct URLs with malicious redirect parameters that bypass the application's normal validation processes, leading unsuspecting users to external sites. This makes the vulnerability particularly dangerous as it can be exploited at scale without requiring advanced technical skills or specialized tools. The impact is amplified when considering that Cybozu Office is typically used in enterprise environments where users may have access to sensitive organizational data, making successful exploitation potentially devastating for affected organizations.
Organizations should implement immediate mitigations including input validation and sanitization of all redirect parameters, implementation of strict URL validation mechanisms, and deployment of web application firewalls to detect and block malicious redirect attempts. The remediation strategy should involve updating to patched versions of Cybozu Office, implementing proper redirect validation logic that ensures all redirect destinations are within approved domains, and conducting user awareness training to recognize potential phishing attempts. Additionally, organizations should review their network monitoring capabilities to detect unusual redirect patterns that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and the potential consequences of inadequate security controls in web applications, aligning with ATT&CK technique T1566 which covers phishing attacks through malicious links and redirects.