CVE-2009-0612 in InterScan Web Security Virtual Appliance
Summary
by MITRE
Trend Micro InterScan Web Security Virtual Appliance (IWSVA) 3.x and InterScan Web Security Suite (IWSS) 3.x, when basic authorization is enabled on the standalone proxy, forwards the Proxy-Authorization header from Windows Media Player, which allows remote web servers to obtain credentials by offering a media stream and then capturing this header.
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Analysis
by VulDB Data Team • 12/02/2017
The vulnerability identified as CVE-2009-0612 represents a critical security flaw in Trend Micro's InterScan Web Security Virtual Appliance and InterScan Web Security Suite versions 3.x. This issue stems from the improper handling of authentication headers within the web proxy functionality, specifically when basic authentication is enabled. The vulnerability manifests when the system forwards the Proxy-Authorization header from Windows Media Player to remote web servers, creating an unintended credential exposure mechanism. This behavior violates fundamental security principles of authentication header management and demonstrates a lack of proper header sanitization within the proxy server implementation.
The technical flaw occurs at the protocol level where the InterScan Web Security appliances act as intermediaries between client requests and remote web servers. When Windows Media Player attempts to access media content through the proxy, it includes a Proxy-Authorization header containing authentication credentials. The vulnerable system fails to strip or properly validate this header before forwarding it to the destination server, effectively allowing any remote web server to capture these credentials through crafted media streams. This vulnerability is classified under CWE-284 as improper access control, specifically related to inadequate protection of authentication mechanisms and represents a classic case of header injection or forwarding without proper validation.
The operational impact of this vulnerability extends beyond simple credential theft, as it creates a persistent security risk for organizations relying on these security appliances. Attackers can exploit this weakness by hosting malicious media content that triggers the credential forwarding behavior, potentially compromising user authentication tokens, corporate network access credentials, or other sensitive authentication data. The vulnerability affects the core functionality of the web proxy, which is designed to protect network traffic, yet paradoxically becomes a vector for credential leakage. This issue directly impacts the confidentiality and integrity of network communications, particularly in enterprise environments where these appliances are deployed to secure web traffic.
Organizations should implement immediate mitigations including disabling basic authentication on the proxy when it is not strictly required, configuring proper header filtering rules to prevent Proxy-Authorization header forwarding, and ensuring that the appliances are updated to patched versions. Network segmentation and monitoring of proxy traffic can help detect anomalous header forwarding patterns. The vulnerability aligns with ATT&CK technique T1566 for credential harvesting through phishing and malicious content delivery, while also representing a failure in network boundary protection. System administrators should also consider implementing additional authentication layers and regular security assessments of proxy configurations to prevent similar issues in other network security devices.