CVE-2016-1343
The XML parser in Cisco Information Server (CIS) 6
Executive Summary
CVE-2016-1343 is a critical severity vulnerability affecting appsec. It is classified as an undisclosed flaw. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"Precogs AI Analysis Engine identifies this vulnerability class through semantic code analysis powered by Code Property Graph (CPG) technology, performing inter-procedural taint tracking to detect injection flaws, broken authentication, and insecure data flows across your entire codebase."
What is this vulnerability?
CVE-2016-1343 is categorized as a critical security flaw with a CVSS base score of 10. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
The XML parser in Cisco Information Server (CIS) 6.2 allows remote attackers to read arbitrary files or cause a denial of service (CPU and memory consumption) via an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue, aka Bug ID CSCuy39059.
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
| Metric | Value |
|---|---|
| CVSS Base Score | 10 (CRITICAL) |
| Vector String | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H |
| Published | April 30, 2016 |
| Last Modified | April 12, 2025 |
| Related CWEs | N/A |
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-2016-1343
- Apply Vendor Patches: Upgrade affected components to their latest, non-vulnerable versions immediately.
- Implement Input Validation: Ensure all user-supplied data is validated, sanitized, and type-checked before processing.
- Deploy Runtime Protection: Use Precogs continuous monitoring to detect exploitation attempts in real time.
- Audit Dependencies: Review and update all third-party libraries and transitive dependencies.
Defending with Precogs AI
Precogs AI Analysis Engine identifies this vulnerability class through semantic code analysis powered by Code Property Graph (CPG) technology, performing inter-procedural taint tracking to detect injection flaws, broken authentication, and insecure data flows across your entire codebase.
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.
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | Untrusted User Input |
| Vector | Input flows through the application logic without sanitization |
| Sink | Execution or Rendering Sink |
| Impact | Application compromise, Logic Bypass, Data Exfiltration |
Vulnerable Code Pattern
# ❌ VULNERABLE: Unsanitized Input Flow
def process_request(request):
user_input = request.GET.get('data')
# Taint sink: processing untrusted data
execute_logic(user_input)
return {"status": "success"}
Secure Code Pattern
# ✅ SECURE: Input Validation & Sanitization
def process_request(request):
user_input = request.GET.get('data')
# Sanitized boundary check
if not is_valid_format(user_input):
raise ValueError("Invalid input format")
sanitized_data = sanitize(user_input)
execute_logic(sanitized_data)
return {"status": "success"}
How Precogs Detects This
Precogs AI Analysis Engine maps untrusted input directly to execution sinks to catch complex application security vulnerabilities.