CVE-2019-4707 in Security Access Manager Appliance
Summary
by MITRE
IBM Security Access Manager Appliance 9.0.7.0 is vulnerable to an XML External Entity Injection (XXE) attack when processing XML data. A remote attacker could exploit this vulnerability to expose sensitive information or consume memory resources. IBM X-Force ID: 172018.
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Analysis
by VulDB Data Team • 03/27/2024
The vulnerability identified as CVE-2019-4707 affects IBM Security Access Manager Appliance version 9.0.7.0 and represents a critical XML External Entity Injection flaw that fundamentally undermines the security posture of the affected system. This vulnerability resides in the appliance's XML processing capabilities, where the system fails to properly validate and sanitize XML input data before parsing. The flaw enables malicious actors to inject external entities into the XML processing pipeline, creating a pathway for unauthorized information disclosure and resource exhaustion attacks. The vulnerability's classification as XXE aligns with CWE-611 which specifically addresses external entity and resource resolution vulnerabilities in XML processors, making this a well-documented and dangerous class of vulnerability that has been exploited in numerous security incidents across various platforms.
The technical exploitation of this vulnerability occurs when the appliance processes XML data containing malicious external entity references that point to internal resources or external servers controlled by the attacker. An attacker can leverage this weakness to perform server-side request forgery attacks, where the appliance makes requests to internal systems that would normally be protected by network segmentation. This creates opportunities for information disclosure attacks where sensitive data such as system configuration files, user credentials, or internal network information can be exfiltrated through the XML processing mechanism. The memory consumption aspect of this vulnerability allows attackers to craft XML payloads that cause excessive resource allocation, potentially leading to denial of service conditions that can disrupt legitimate access to the security appliance. The attack surface is particularly concerning because the appliance serves as a central access control point, making successful exploitation potentially devastating for organizational security infrastructure.
The operational impact of CVE-2019-4707 extends beyond simple information disclosure to encompass potential complete system compromise and service disruption. Organizations relying on IBM Security Access Manager Appliance for authentication and access control face significant risk as attackers could potentially bypass authentication mechanisms or gain unauthorized access to protected resources. The vulnerability's remote exploitability means that attackers do not require physical access or network proximity to the appliance, making it particularly dangerous for organizations with distributed networks or cloud deployments. The memory consumption aspect creates additional operational concerns as attackers can exhaust system resources and cause legitimate users to experience service interruptions. This vulnerability directly impacts the appliance's ability to function as a security control, potentially leaving organizations exposed to further attacks while the appliance is compromised. The attack pattern aligns with ATT&CK technique T1059.007 for XML External Entity Injection, which is categorized under the execution and privilege escalation domains of the adversary tactics framework.
Mitigation strategies for CVE-2019-4707 should prioritize immediate patch application from IBM, as the vendor has released security fixes addressing this specific vulnerability. Organizations should implement network segmentation to limit access to the appliance to only necessary systems and users, reducing the attack surface available to potential exploiters. Input validation and sanitization measures should be enhanced to prevent XML data from containing external entity references, particularly when processing untrusted input. Security monitoring should be implemented to detect unusual XML processing patterns or excessive resource consumption that might indicate exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in the broader security infrastructure. The implementation of web application firewalls and XML validation rules can provide additional layers of protection against XXE attacks. Organizations should also consider implementing strict access controls and monitoring for the appliance's administrative interfaces, as successful exploitation could potentially lead to complete administrative access to the security appliance. Compliance with industry standards such as NIST SP 800-53 and ISO 27001 requires organizations to maintain up-to-date security measures against known vulnerabilities like CVE-2019-4707, making this remediation a critical operational security requirement.