CVE-2008-4515 in K9 Web Protection
Summary
by MITRE
Blue Coat K9 Web Protection 4.0.230 Beta relies on client-side JavaScript as a protection mechanism, which allows remote attackers to bypass authentication and access the (1) summary, (2) detail, (3) overrides, and (4) pwemail pages by disabling JavaScript.
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Analysis
by VulDB Data Team • 08/18/2019
The vulnerability identified as CVE-2008-4515 represents a critical security flaw in Blue Coat K9 Web Protection 4.0.230 Beta where the system incorrectly relies on client-side JavaScript for access control enforcement. This design decision creates a fundamental weakness in the security architecture, as the authentication mechanism can be easily circumvented by malicious actors who simply disable JavaScript in their web browsers. The vulnerability affects four specific administrative pages within the web protection system including summary, detail, overrides, and pwemail interfaces, all of which are accessible without proper authentication when JavaScript is disabled. This represents a classic example of insecure client-side validation that violates fundamental security principles.
The technical flaw stems from the improper implementation of security controls where the system assumes that client-side JavaScript will enforce access restrictions. According to CWE-602, this vulnerability maps directly to client-side enforcement of server-side security checks, which is a well-documented weakness in web application security. The system fails to implement proper server-side authentication verification, instead depending on client-side mechanisms that can be easily manipulated or disabled by attackers. This creates a scenario where the security boundary is effectively bypassed, allowing unauthorized access to administrative functions that should only be available to authenticated users. The vulnerability demonstrates a failure to implement defense in depth principles, where multiple layers of security should be present to protect against single points of failure.
The operational impact of this vulnerability is significant as it allows remote attackers to gain unauthorized access to critical administrative functions of the Blue Coat K9 Web Protection system. Attackers can access summary reports, detailed configuration information, override settings, and password recovery functionality without proper authentication, potentially leading to complete system compromise. This vulnerability enables an attacker to manipulate the web filtering policies, view sensitive reports, and potentially gain control over the entire filtering infrastructure. The impact extends beyond simple information disclosure, as the ability to modify override settings could allow attackers to bypass security policies, while access to password recovery functions could lead to credential compromise. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and T1566 which covers credential access through social engineering or exploitation of weak authentication mechanisms.
The mitigation strategies for this vulnerability require immediate implementation of proper server-side authentication enforcement. Organizations should ensure that all administrative interfaces require robust server-side verification before granting access to sensitive functions. This includes implementing proper session management, enforcing authentication at the server level, and removing reliance on client-side JavaScript for security decisions. The system should be updated to version 4.0.230 or later where this vulnerability has been addressed. Network segmentation and additional monitoring should be implemented to detect unauthorized access attempts. Security controls should be designed with defense in depth principles, ensuring that the failure of one security mechanism does not compromise the entire system. Regular security assessments should verify that authentication mechanisms are properly enforced server-side rather than relying on client-side controls that can be easily bypassed. This vulnerability highlights the importance of following secure coding practices and avoiding the use of client-side mechanisms for enforcing security policies.