CVE-2017-12232
CWE-399 in A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15
Executive Summary
CVE-2017-12232 is a medium severity vulnerability affecting appsec. It is classified as CWE-399. This vulnerability is actively being exploited in the wild.
Precogs AI Insight
"A protocol implementation flaw in ISR G2 routers allows unauthenticated packet manipulation. Attackers bypass access control lists to pivot through the router into internal networks. Precogs API Security Engine comprehensively audits routing control plane boundaries."
What is this vulnerability?
CVE-2017-12232 is categorized as a medium CWE-399 flaw with a CVSS base score of 6.5. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15.0 through 15.6 could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a misclassification of Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc03809.
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 | 6.5 (MEDIUM) |
| Vector String | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Published | September 29, 2017 |
| Last Modified | April 22, 2026 |
| Related CWEs | CWE-399 |
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-2017-12232
- Apply Vendor Patches Immediately: This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog. Apply updates per vendor instructions.
- Verify Patch Deployment: Confirm all instances are updated using Precogs continuous monitoring.
- Review Audit Logs: Investigate historical access logs for indicators of compromise related to this attack surface.
- Implement Defense-in-Depth: Deploy WAF rules, network segmentation, and endpoint detection to limit blast radius.
Defending with Precogs AI
A protocol implementation flaw in ISR G2 routers allows unauthenticated packet manipulation. Attackers bypass access control lists to pivot through the router into internal networks. Precogs API Security Engine comprehensively audits routing control plane boundaries.
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