CVE-2001-0519 in eSafe Gateway
Summary
by MITRE
Aladdin eSafe Gateway versions 2.x allows a remote attacker to circumvent HTML SCRIPT filtering via a special arrangement of HTML tags which includes SCRIPT tags embedded within other SCRIPT tags.
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Analysis
by VulDB Data Team • 12/09/2024
The vulnerability described in CVE-2001-0519 represents a critical security flaw in Aladdin eSafe Gateway version 2.x that undermines the system's HTML content filtering capabilities. This issue specifically targets the gateway's ability to prevent malicious script execution by allowing attackers to bypass HTML SCRIPT tag filtering mechanisms through sophisticated tag manipulation techniques. The vulnerability exploits a fundamental weakness in the content inspection process that fails to properly validate nested HTML structures, creating a pathway for malicious code injection that could compromise the entire security infrastructure.
The technical flaw in this vulnerability stems from the inadequate parsing and validation of nested HTML elements within the eSafe Gateway's filtering engine. When SCRIPT tags are embedded within other SCRIPT tags or manipulated through specific HTML tag arrangements, the gateway's content inspection system fails to recognize the malicious intent behind such constructions. This represents a classic example of improper input validation and sanitization that allows attackers to craft payloads that evade security controls. The vulnerability operates at the application layer and specifically targets the HTML filtering functionality, making it particularly dangerous for web-based security appliances that rely on proper content inspection.
The operational impact of this vulnerability extends far beyond simple bypass of security controls, as it fundamentally undermines the trust model of the eSafe Gateway security system. Remote attackers can leverage this weakness to execute malicious scripts within the protected environment, potentially leading to complete system compromise, data exfiltration, or unauthorized access to protected resources. The vulnerability's remote exploitability means that attackers do not require physical access or local privileges to exploit the flaw, making it particularly dangerous for network security appliances that are designed to protect against external threats. Organizations relying on this gateway for web content filtering may find their entire security posture compromised, as the system fails to properly filter content that would normally be blocked by its HTML filtering mechanisms.
The vulnerability aligns with CWE-20, which describes improper input validation, and demonstrates characteristics consistent with attack patterns found in the MITRE ATT&CK framework under the T1059.007 technique for scripting languages. This classification indicates that the vulnerability enables adversaries to execute malicious code through script injection techniques, bypassing traditional security controls. Organizations should implement immediate mitigations including upgrading to patched versions of the eSafe Gateway software, implementing additional content filtering layers, and conducting thorough security assessments of their web filtering infrastructure. Network segmentation and additional monitoring controls should be deployed to detect potential exploitation attempts, while security teams should consider the broader implications for their web security posture and ensure that similar vulnerabilities are not present in other components of their security infrastructure. The vulnerability serves as a reminder of the critical importance of proper HTML parsing and validation in security appliances, particularly those designed to filter potentially malicious content from web traffic.