CVE-2021-43269
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code by injecting malicious JavaScript through proxy configuration in Code42 applications. It affects Code42 app versions before 8.8.0, specifically impacting Incydr Basic, Advanced, and Gov F1; CrashPlan Cloud; and CrashPlan for Small Business.
💻 Affected Systems
- Incydr Basic
- Incydr Advanced
- Incydr Gov F1
- CrashPlan Cloud
- CrashPlan for Small Business
📦 What is this software?
Code42 by Code42
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over affected devices, enabling data theft, ransomware deployment, or lateral movement within networks.
Likely Case
Attacker redirects traffic through malicious proxy to intercept sensitive data, potentially leading to credential theft and data exfiltration.
If Mitigated
Limited impact with proper network segmentation and endpoint protection, potentially only affecting isolated systems.
🎯 Exploit Status
Exploitation requires ability to modify proxy settings, which typically requires some level of access or social engineering.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.8.0 and later
Restart Required: Yes
Instructions:
1. Download Code42 app version 8.8.0 or later from official Code42 sources. 2. Install the update on all affected systems. 3. Restart the Code42 service or reboot systems as required.
🔧 Temporary Workarounds
Restrict Proxy Configuration Access
allLimit ability to modify proxy settings through group policies or configuration management
Network Segmentation
allIsolate Code42 clients from critical systems to limit lateral movement potential
🧯 If You Can't Patch
- Implement strict network monitoring for unusual proxy configuration changes
- Deploy endpoint detection and response (EDR) solutions to detect malicious behavior
🔍 How to Verify
Check if Vulnerable:
Check Code42 app version in application settings or via command line: code42 --versionCheck Version:
code42 --versionVerify Fix Applied:
Verify version is 8.8.0 or higher and check that proxy configuration settings are properly validated📡 Detection & Monitoring
Log Indicators:
- Unexpected proxy configuration changes
- Code42 service restarts with unusual parameters
- JavaScript execution errors in Code42 logs
Network Indicators:
- Traffic redirected to unexpected proxy servers
- Unusual outbound connections from Code42 clients
SIEM Query:
source="code42" AND (event="proxy_config_change" OR event="javascript_execution")🔗 References
- https://support.code42.com/Terms_and_conditions/Code42_customer_support_resources/Code42_security_advisories/Arbitrary_code_execution_via_malicious_Code42_app_proxy_configuration
- https://www.code42.com/r/support/CVE-2021-43269
- https://support.code42.com/Terms_and_conditions/Code42_customer_support_resources/Code42_security_advisories/Arbitrary_code_execution_via_malicious_Code42_app_proxy_configuration
- https://www.code42.com/r/support/CVE-2021-43269
