CVE-2020-12080 – CVE-2020-12080 is a Denial of Service vulnerabi... (How to Fix)

Q: What is the severity of CVE-2020-12080?

CVE-2020-12080 has a CVSS score of 7.5 (HIGH). CVE-2020-12080 is a Denial of Service vulnerability in FlexNet Publisher's lmadmin.exe service. Attackers can send specially crafted messages to crash the licensing service, disrupting software licensing operations. Organizations using FlexNet Publisher version 11.16.6 for software license management are affected.

📋 TL;DR

CVE-2020-12080 is a Denial of Service vulnerability in FlexNet Publisher's lmadmin.exe service. Attackers can send specially crafted messages to crash the licensing service, disrupting software licensing operations. Organizations using FlexNet Publisher version 11.16.6 for software license management are affected.

💻 Affected Systems

Products:

FlexNet Publisher

Versions: Version 11.16.6 specifically

Operating Systems: Windows, Linux, Unix systems running FlexNet Publisher

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects the lmadmin.exe component. Earlier versions may also be vulnerable but not confirmed. Later versions starting with 11.17.0 are patched.

📦 What is this software?

Flexnet Publisher by Flexera

View all CVEs affecting Flexnet Publisher →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete disruption of software licensing services, preventing legitimate users from accessing licensed software across the organization until service is restored.

🟠

Likely Case

Temporary service interruption affecting software license validation and management, requiring service restart and potentially manual intervention.

🟢

If Mitigated

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

🌐 Internet-Facing: HIGH if lmadmin.exe is exposed to untrusted networks, as the exploit requires only network access to the service port.

🏢 Internal Only: MEDIUM as internal attackers or compromised systems could still exploit the vulnerability to disrupt licensing services.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires network access to the lmadmin service port (typically 27000-27009). The vulnerability is in message protocol handling, making exploitation straightforward for attackers with network access.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 11.17.0 and later

Vendor Advisory: https://community.flexera.com/t5/FlexNet-Publisher-Knowledge-Base/CVE-2020-12080-Remediated-in-FlexNet-Publisher/ta-p/143873

Restart Required: Yes

Instructions:

1. Download FlexNet Publisher 2020 R2 (11.17.0) or later from Flexera. 2. Backup current configuration. 3. Install the updated version following vendor instructions. 4. Restart lmadmin service. 5. Verify service functionality.

🔧 Temporary Workarounds

Network Segmentation

all

Restrict network access to lmadmin service ports (27000-27009) to only trusted systems

# Example firewall rule (Windows): New-NetFirewallRule -DisplayName "Block lmadmin external" -Direction Inbound -LocalPort 27000-27009 -Protocol TCP -Action Block -RemoteAddress Any

Service Monitoring and Auto-restart

linux

Implement monitoring to detect and automatically restart crashed lmadmin service

# Example monitoring script: while true; do if ! pgrep -x "lmadmin" > /dev/null; then systemctl restart flexnet-publisher; fi; sleep 30; done

🧯 If You Can't Patch

Implement strict network access controls to limit connections to lmadmin service only from trusted IP addresses
Deploy intrusion detection systems to monitor for suspicious traffic patterns targeting the lmadmin service ports

🔍 How to Verify

Check if Vulnerable:

Check FlexNet Publisher version: On Windows: Check installed programs list for FlexNet Publisher version. On Linux: Run 'lmadmin -version' or check package manager.

Check Version:

Windows: Check Programs and Features. Linux: 'lmadmin -version' or 'rpm -qa | grep flexnet' or 'dpkg -l | grep flexnet'

Verify Fix Applied:

Verify version is 11.17.0 or later and lmadmin service runs without crashing under normal load.

📡 Detection & Monitoring

Log Indicators:

Unexpected lmadmin service crashes
Error messages related to message parsing or protocol handling
Service restart events in system logs

Network Indicators:

Unusual traffic patterns to port 27000-27009
Multiple connection attempts followed by service unavailability

SIEM Query:

source="*lmadmin*" AND ("crash" OR "unexpected termination" OR "service stopped") OR destination_port IN (27000, 27001, 27002, 27003, 27004, 27005, 27006, 27007, 27008, 27009) AND bytes_transferred > 1000

📊 Metadata

CVE ID: CVE-2020-12080

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-20

Published: September 17, 2021

Last Updated: November 21, 2024

🔗 References

https://community.flexera.com/t5/FlexNet-Publisher-Knowledge-Base/CVE-2020-12080-Remediated-in-FlexNet-Publisher/ta-p/143873 Vendor Advisory
https://community.flexera.com/t5/FlexNet-Publisher-News/FlexNet-Publisher-2020-R2-11-17-0-is-here/ba-p/144017/jump-to/first-unread-message Release Notes,Vendor Advisory
https://www.tenable.com/security/research/tra-2020-28 Exploit,Third Party Advisory
https://community.flexera.com/t5/FlexNet-Publisher-Knowledge-Base/CVE-2020-12080-Remediated-in-FlexNet-Publisher/ta-p/143873 Vendor Advisory
https://community.flexera.com/t5/FlexNet-Publisher-News/FlexNet-Publisher-2020-R2-11-17-0-is-here/ba-p/144017/jump-to/first-unread-message Release Notes,Vendor Advisory
https://www.tenable.com/security/research/tra-2020-28 Exploit,Third Party Advisory

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