CVE-2019-13608

What is this vulnerability?

CVE-2019-13608 is categorized as a high XML External Entity (XXE) flaw with a CVSS base score of 7.5. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

Citrix StoreFront Server before 1903, 7.15 LTSR before CU4 (3.12.4000), and 7.6 LTSR before CU8 (3.0.8000) allows XXE attacks.

This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.

Risk Assessment

Impact on Systems

✅ Data Exfiltration: Attackers can extract sensitive data from backend databases, configuration files, or internal services.

✅ Authentication Bypass: Exploiting this flaw may allow unauthorized access to protected resources and administrative interfaces.

✅ Lateral Movement: Once initial access is gained, attackers can pivot to internal systems and escalate privileges.

How to Fix and Mitigate CVE-2019-13608

1. Apply Vendor Patches Immediately: This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog. Apply updates per vendor instructions.
2. Verify Patch Deployment: Confirm all instances are updated using Precogs continuous monitoring.
3. Review Audit Logs: Investigate historical access logs for indicators of compromise related to this attack surface.
4. Implement Defense-in-Depth: Deploy WAF rules, network segmentation, and endpoint detection to limit blast radius.

Defending with Precogs AI

Citrix StoreFront Server incorrectly implements access controls, allowing attackers to bypass authentication. Adversaries exploit this to access sensitive applications without valid credentials. Precogs API Security Engine comprehensively audits session boundaries and authorization logic.

Use Precogs to continuously scan your codebase, binaries, APIs, and infrastructure for this vulnerability class and related attack patterns. Our AI-powered detection engine combines static analysis with threat intelligence to identify exploitable weaknesses before attackers do.

Start scanning with Precogs →

Vulnerability Code Signature

Attack Data Flow

Vulnerable Code Pattern

// ❌ VULNERABLE: XXE Injection
public void parseXml(InputStream is) throws Exception {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    // Taint sink: default configuration allows external entities
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document doc = builder.parse(is);
}

Secure Code Pattern

// ✅ SECURE: Safe XML Parsing
public void parseXml(InputStream is) throws Exception {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    // Sanitized configuration: disable external entities
    factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document doc = builder.parse(is);
}

How Precogs Detects This

Precogs AI Analysis Engine identifies unsafe XML parsing configurations and XXE injection weaknesses via inter-procedural taint tracking.\n