CVE-2020-13583 – A denial-of-service vulnerability in Micrium uC... (How to Fix)

Q: What is the severity of CVE-2020-13583?

CVE-2020-13583 has a CVSS score of 7.5 (HIGH). A denial-of-service vulnerability in Micrium uC-HTTP 3.01.00 allows attackers to crash the HTTP server by sending specially crafted HTTP requests. This affects any system running the vulnerable version of uC-HTTP server software, potentially disrupting web services and applications.

📋 TL;DR

A denial-of-service vulnerability in Micrium uC-HTTP 3.01.00 allows attackers to crash the HTTP server by sending specially crafted HTTP requests. This affects any system running the vulnerable version of uC-HTTP server software, potentially disrupting web services and applications.

💻 Affected Systems

Products:

Micrium uC-HTTP

Versions: 3.01.00

Operating Systems: Any OS running uC-HTTP (typically embedded systems)

Default Config Vulnerable: ⚠️ Yes

Notes: Affects the HTTP server component specifically; other services may continue functioning.

📦 What is this software?

Uc Http by Micrium

View all CVEs affecting Uc Http →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete HTTP service disruption requiring server restart, potentially affecting all web-based functionality on the device.

🟠

Likely Case

Temporary service outage affecting web interfaces or API endpoints until the service is restarted.

🟢

If Mitigated

Minimal impact with proper network segmentation and monitoring allowing quick detection and response.

🌐 Internet-Facing: HIGH - HTTP servers exposed to the internet are directly accessible to attackers.

🏢 Internal Only: MEDIUM - Internal attackers or compromised internal systems could still exploit this vulnerability.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

The vulnerability requires sending a crafted HTTP request to the server, which is straightforward for attackers with network access.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 3.01.01 or later

Vendor Advisory: https://www.silabs.com/security

Restart Required: Yes

Instructions:

1. Download updated uC-HTTP version from Silicon Labs. 2. Replace vulnerable uC-HTTP library. 3. Recompile and redeploy application. 4. Restart the HTTP service.

🔧 Temporary Workarounds

Network Filtering

all

Block or filter suspicious HTTP requests at network perimeter

Service Monitoring

all

Implement automatic service restart on crash detection

🧯 If You Can't Patch

Implement network segmentation to isolate vulnerable systems
Deploy web application firewall (WAF) to filter malicious HTTP requests

🔍 How to Verify

Check if Vulnerable:

Check uC-HTTP library version; if version is 3.01.00, system is vulnerable.

Check Version:

Check application build configuration or library files for uC-HTTP version

Verify Fix Applied:

Verify uC-HTTP version is 3.01.01 or later and test HTTP service functionality.

📡 Detection & Monitoring

Log Indicators:

HTTP server crash logs
Unexpected service restarts
Failed HTTP requests with unusual patterns

Network Indicators:

Multiple HTTP requests with malformed headers or unusual patterns
Sudden drop in HTTP service availability

SIEM Query:

source="http_server" AND (event="crash" OR event="restart")

📊 Metadata

CVE ID: CVE-2020-13583

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-476

Published: February 10, 2021

Last Updated: November 21, 2024

🔗 References

https://talosintelligence.com/vulnerability_reports/TALOS-2020-1194 Exploit,Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2020-1194 Exploit,Third Party Advisory

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