CVE-2021-45034 – This vulnerability allows unauthenticated attac... (How to Fix)

Q: How do I fix CVE-2021-45034?

1. Download firmware V16.20 or later from Siemens support portal. 2. Backup current configuration. 3. Apply firmware update following Siemens documentation. 4. Verify successful update and restore configuration if needed.

Q: What is the severity of CVE-2021-45034?

CVE-2021-45034 has a CVSS score of 7.5 (HIGH). This vulnerability allows unauthenticated attackers to access privileged logfiles and diagnostic data on Siemens CP-8000 and CP-8021/8022 master modules. Attackers can download sensitive files by guessing or discovering download links. All versions before V16.20 of the affected products are vulnerable.

📋 TL;DR

This vulnerability allows unauthenticated attackers to access privileged logfiles and diagnostic data on Siemens CP-8000 and CP-8021/8022 master modules. Attackers can download sensitive files by guessing or discovering download links. All versions before V16.20 of the affected products are vulnerable.

💻 Affected Systems

Products:

CP-8000 MASTER MODULE WITH I/O -25/+70°C
CP-8000 MASTER MODULE WITH I/O -40/+70°C
CP-8021 MASTER MODULE
CP-8022 MASTER MODULE WITH GPRS

Versions: All versions < V16.20

Operating Systems: Embedded/Industrial OS

Default Config Vulnerable: ⚠️ Yes

Notes: Affects web server component of these industrial control modules.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers obtain sensitive system information, credentials, or configuration details that could enable further attacks, potentially leading to industrial control system compromise.

🟠

Likely Case

Unauthorized access to diagnostic logs containing system information, user activities, or configuration details that could aid reconnaissance for further attacks.

🟢

If Mitigated

Limited information disclosure with no direct system compromise if logs contain minimal sensitive data.

🌐 Internet-Facing: HIGH - Web server accessible from internet with no authentication required for file downloads.

🏢 Internal Only: MEDIUM - Internal attackers can still exploit without credentials, but requires network access.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires guessing or discovering download URLs, which may be predictable or discoverable through enumeration.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: V16.20 or later

Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-324998.pdf

Restart Required: Yes

Instructions:

1. Download firmware V16.20 or later from Siemens support portal. 2. Backup current configuration. 3. Apply firmware update following Siemens documentation. 4. Verify successful update and restore configuration if needed.

🔧 Temporary Workarounds

Network Segmentation

all

Restrict network access to affected devices to authorized networks only.

Web Server Access Control

all

Configure firewall rules to block external access to web server ports (typically 80/443).

🧯 If You Can't Patch

Isolate affected devices in dedicated network segments with strict access controls.
Implement network monitoring for unusual access patterns to web server endpoints.

🔍 How to Verify

Check if Vulnerable:

Check device firmware version via web interface or serial console. If version is below V16.20, device is vulnerable.

Check Version:

Check via web interface at /status or via serial console using manufacturer-specific commands.

Verify Fix Applied:

Confirm firmware version is V16.20 or higher via device interface and test that unauthenticated file downloads are no longer possible.

📡 Detection & Monitoring

Log Indicators:

Unauthenticated access to file download endpoints
Multiple failed attempts to access protected resources

Network Indicators:

HTTP GET requests to logfile/diagnostic endpoints without authentication
Unusual file download patterns from device IP

SIEM Query:

source_ip=[device_ip] AND (url_path CONTAINS "log" OR url_path CONTAINS "diagnostic") AND http_method=GET AND auth_status="none"

📊 Metadata

CVE ID: CVE-2021-45034

CVSS v3 Score: 7.5 (HIGH)

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

CWE: CWE-284

Published: January 11, 2022

Last Updated: November 21, 2024

🔗 References

http://packetstormsecurity.com/files/166743/Siemens-A8000-CP-8050-CP-8031-SICAM-WEB-Missing-File-Download-Missing-Authentication.html Exploit,Third Party Advisory,VDB Entry
http://seclists.org/fulldisclosure/2022/Apr/20 Exploit,Mailing List,Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-324998.pdf Patch,Vendor Advisory
http://packetstormsecurity.com/files/166743/Siemens-A8000-CP-8050-CP-8031-SICAM-WEB-Missing-File-Download-Missing-Authentication.html Exploit,Third Party Advisory,VDB Entry
http://seclists.org/fulldisclosure/2022/Apr/20 Exploit,Mailing List,Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-324998.pdf Patch,Vendor Advisory

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