CVE-2021-42631 – CVE-2021-42631 is a deserialization vulnerabili... (How to Fix)

Q: What is the severity of CVE-2021-42631?

CVE-2021-42631 has a CVSS score of 8.1 (HIGH). CVE-2021-42631 is a deserialization vulnerability in PrinterLogic Web Stack that allows unauthenticated attackers to execute arbitrary code remotely. This affects PrinterLogic Web Stack versions 19.1.1.13 SP9 and below. Organizations using vulnerable PrinterLogic printer management systems are at risk.

📋 TL;DR

CVE-2021-42631 is a deserialization vulnerability in PrinterLogic Web Stack that allows unauthenticated attackers to execute arbitrary code remotely. This affects PrinterLogic Web Stack versions 19.1.1.13 SP9 and below. Organizations using vulnerable PrinterLogic printer management systems are at risk.

💻 Affected Systems

Products:

PrinterLogic Web Stack

Versions: 19.1.1.13 SP9 and below

Operating Systems: Windows Server (typical deployment), Linux (possible deployments)

Default Config Vulnerable: ⚠️ Yes

Notes: All deployments with vulnerable versions are affected regardless of configuration.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system compromise allowing attackers to install malware, steal credentials, pivot to internal networks, and disrupt printing infrastructure.

🟠

Likely Case

Attackers gain initial foothold on the network, deploy ransomware or crypto-miners, and potentially move laterally to other systems.

🟢

If Mitigated

Attack attempts are blocked at network perimeter, but internal systems remain vulnerable if exposed internally.

🌐 Internet-Facing: HIGH - Pre-authentication RCE on internet-facing systems allows complete compromise without credentials.

🏢 Internal Only: HIGH - Even internally, this provides easy initial access for attackers who breach perimeter defenses.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Deserialization vulnerabilities typically have reliable exploitation paths and this is pre-authentication.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Versions after 19.1.1.13 SP9

Vendor Advisory: https://www.printerlogic.com/security-bulletin/

Restart Required: Yes

Instructions:

1. Download latest PrinterLogic Web Stack version from vendor portal. 2. Backup current configuration. 3. Install update following vendor documentation. 4. Restart services. 5. Verify functionality.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate PrinterLogic Web Stack from internet and restrict internal access to authorized users only.

Application Firewall Rules

all

Implement WAF rules to block suspicious deserialization patterns in HTTP requests.

🧯 If You Can't Patch

Implement strict network access controls to limit exposure to only necessary users/systems
Deploy intrusion detection/prevention systems to monitor for exploitation attempts

🔍 How to Verify

Check if Vulnerable:

Check PrinterLogic Web Stack version in administration console or via installed program version.

Check Version:

Check via PrinterLogic Admin Console or Windows: wmic product where name='PrinterLogic Web Stack' get version

Verify Fix Applied:

Verify version is above 19.1.1.13 SP9 and test printing functionality remains operational.

📡 Detection & Monitoring

Log Indicators:

Unusual deserialization errors in application logs
Suspicious process creation from web service account
Unexpected network connections from PrinterLogic server

Network Indicators:

HTTP requests with serialized objects to PrinterLogic endpoints
Outbound connections from PrinterLogic server to suspicious IPs

SIEM Query:

source='printerlogic' AND (event_id='deserialization_error' OR process_name='cmd.exe' OR process_name='powershell.exe')

📊 Metadata

CVE ID: CVE-2021-42631

CVSS v3 Score: 8.1 (HIGH)

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

CWE: CWE-502

Published: January 31, 2022

Last Updated: November 21, 2024

🔗 References

http://printerlogic.com Vendor Advisory
https://portswigger.net/daily-swig/printerlogic-vendor-addresses-triple-rce-threat-against-all-connected-endpoints Press/Media Coverage,Third Party Advisory
https://securityaffairs.co/wordpress/127194/security/printerlogic-printer-management-suite-flaws.html Third Party Advisory
https://thecyberthrone.in/2022/01/26/printerlogic-%F0%9F%96%A8-fixes-critical-vulnerabilities-in-its-suite/?utm_source=rss&utm_medium=rss&utm_campaign=printerlogic-%25f0%259f%2596%25a8-fixes-critical-vulnerabilities-in-its-suite Press/Media Coverage,Third Party Advisory
https://www.printerlogic.com/security-bulletin/ Vendor Advisory
https://www.securityweek.com/printerlogic-patches-code-execution-flaws-printer-management-suite Press/Media Coverage,Third Party Advisory
https://www.yahooinc.com/paranoids/paranoids-vulnerability-research-printerlogic-issues-security-alert/ Exploit,Press/Media Coverage,Third Party Advisory
http://printerlogic.com Vendor Advisory
https://portswigger.net/daily-swig/printerlogic-vendor-addresses-triple-rce-threat-against-all-connected-endpoints Press/Media Coverage,Third Party Advisory
https://securityaffairs.co/wordpress/127194/security/printerlogic-printer-management-suite-flaws.html Third Party Advisory
https://thecyberthrone.in/2022/01/26/printerlogic-%F0%9F%96%A8-fixes-critical-vulnerabilities-in-its-suite/?utm_source=rss&utm_medium=rss&utm_campaign=printerlogic-%25f0%259f%2596%25a8-fixes-critical-vulnerabilities-in-its-suite Press/Media Coverage,Third Party Advisory
https://www.printerlogic.com/security-bulletin/ Vendor Advisory
https://www.securityweek.com/printerlogic-patches-code-execution-flaws-printer-management-suite Press/Media Coverage,Third Party Advisory
https://www.yahooinc.com/paranoids/paranoids-vulnerability-research-printerlogic-issues-security-alert/ Exploit,Press/Media Coverage,Third Party Advisory

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🔗 Related Vulnerabilities

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📋 TL;DR

💻 Affected Systems

📦 What is this software?

Virtual Appliance by Printerlogic

Web Stack by Printerlogic

Web Stack by Printerlogic

Web Stack by Printerlogic

Web Stack by Printerlogic

Web Stack by Printerlogic

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Network Segmentation

Application Firewall Rules

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

🔗 Related Vulnerabilities