CVE-2020-29495
📋 TL;DR
CVE-2020-29495 is a critical OS command injection vulnerability in Dell EMC Avamar Server's Fitness Analyzer component. Remote unauthenticated attackers can execute arbitrary operating system commands with high privileges, potentially compromising both the application and underlying OS. Organizations running affected Avamar Server versions 19.1-19.3 are vulnerable.
💻 Affected Systems
- Dell EMC Avamar Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the Avamar Server and underlying operating system, allowing attackers to steal backup data, deploy ransomware, pivot to other systems, and maintain persistent access.
Likely Case
Remote code execution leading to data exfiltration, installation of backdoors, and disruption of backup operations.
If Mitigated
Limited impact if network segmentation, strict firewall rules, and proper access controls prevent external access to vulnerable systems.
🎯 Exploit Status
The vulnerability requires no authentication and is in a web-accessible component, making exploitation straightforward for attackers who can reach the service.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 19.3 (specific fixed version in vendor advisory)
Vendor Advisory: https://www.dell.com/support/kbdoc/en-us/000181806/dsa-2020-272-dell-emc-avamar-server-security-update-for-multiple-vulnerabilities
Restart Required: Yes
Instructions:
1. Download the security update from Dell's support portal. 2. Apply the update following Dell's Avamar Server update procedures. 3. Restart the Avamar Server as required by the update process.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to Avamar Server to only trusted management networks and backup clients.
Firewall Rules
allImplement strict firewall rules to block external access to Avamar Server management interfaces.
🧯 If You Can't Patch
- Isolate the Avamar Server on a dedicated VLAN with strict access controls
- Implement network-based intrusion prevention systems (IPS) to detect and block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check Avamar Server version via the Avamar Administration Console or CLI. If version is 19.1, 19.2, or 19.3, the system is vulnerable.Check Version:
On Avamar Server: avmgr versionVerify Fix Applied:
Verify the Avamar Server version has been updated to a version beyond 19.3 as specified in Dell's security advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Unexpected processes spawned by Avamar services
- Failed authentication attempts followed by successful command execution
Network Indicators:
- Unusual outbound connections from Avamar Server
- Suspicious HTTP requests to Fitness Analyzer endpoints
SIEM Query:
source="avamar_logs" AND (event="command_injection" OR process="unexpected_process")