CVE-2019-0786
Improper Input Validation in An elevation of privilege vulnerability exists in the Microsoft Server Message Block (SMB) Server when an attacker with valid credentials attempts to open a specially crafted file over the SMB protocol on the same machine, aka 'SMB Server Elevation of Privilege Vulnerability'
Executive Summary
CVE-2019-0786 is a critical severity vulnerability affecting appsec. It is classified as CWE-20. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"Microsoft Server Message Block (SMB) Server contains an elevation of privilege vulnerability. Authenticated attackers open a specially crafted file over SMB, triggering a flaw that allows them to execute arbitrary code with elevated permissions. Precogs Binary SAST uncovers missing boundary validations in core networking protocols."
What is this vulnerability?
CVE-2019-0786 is categorized as a critical Improper Input Validation flaw with a CVSS base score of 9.8. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
An elevation of privilege vulnerability exists in the Microsoft Server Message Block (SMB) Server when an attacker with valid credentials attempts to open a specially crafted file over the SMB protocol on the same machine, aka 'SMB Server Elevation of Privilege Vulnerability'.
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 | 9.8 (CRITICAL) |
| Vector String | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Published | April 9, 2019 |
| Last Modified | November 21, 2024 |
| Related CWEs | CWE-20 |
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-2019-0786
- 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
Microsoft Server Message Block (SMB) Server contains an elevation of privilege vulnerability. Authenticated attackers open a specially crafted file over SMB, triggering a flaw that allows them to execute arbitrary code with elevated permissions. Precogs Binary SAST uncovers missing boundary validations in core networking protocols.
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.\n