CVE-2020-5344: Dell iDRAC Buffer Overflow Vulnerability

CVE-2020-5344 Overview

CVE-2020-5344 is a stack-based buffer overflow vulnerability affecting Dell EMC iDRAC (Integrated Dell Remote Access Controller) versions 7, 8, and 9. The vulnerability exists in firmware versions prior to 2.65.65.65 (iDRAC7), 2.70.70.70 (iDRAC8), and 4.00.00.00 (iDRAC9). An unauthenticated remote attacker can exploit this vulnerability to crash the affected process or execute arbitrary code on the system by sending specially crafted input data to the management interface.

Critical Impact

This unauthenticated remote code execution vulnerability in server management controllers poses severe risks to enterprise infrastructure, potentially allowing attackers to gain complete control over server hardware management interfaces without any authentication.

Affected Products

• Dell iDRAC7 Firmware versions prior to 2.65.65.65
• Dell iDRAC8 Firmware versions prior to 2.70.70.70
• Dell iDRAC9 Firmware versions prior to 4.00.00.00

Discovery Timeline

• 2020-03-31 - CVE-2020-5344 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2020-5344

Vulnerability Analysis

This vulnerability is classified under CWE-121 (Stack-based Buffer Overflow) and CWE-787 (Out-of-bounds Write). The flaw resides in the Dell EMC iDRAC firmware, which provides out-of-band server management capabilities. When processing certain input data, the affected iDRAC firmware fails to properly validate input boundaries, allowing data to overflow the allocated stack buffer.

The iDRAC interface is a critical management component embedded in Dell PowerEdge servers, providing administrators with remote access to server hardware regardless of the operating system state. Because this vulnerability requires no authentication and can be exploited remotely over the network, it represents a significant threat to enterprise data center environments where iDRAC interfaces are exposed.

Root Cause

The root cause of CVE-2020-5344 is improper bounds checking during input processing within the iDRAC firmware. When handling specially crafted network data, the firmware copies user-supplied input into a fixed-size stack buffer without adequate length validation. This allows an attacker to write beyond the allocated buffer boundaries, corrupting adjacent stack memory including return addresses and saved registers.

Attack Vector

The vulnerability is exploitable remotely over the network without requiring authentication or user interaction. An attacker with network access to the iDRAC management interface (typically on port 443 for HTTPS or other iDRAC service ports) can send specially crafted packets to trigger the buffer overflow condition.

The attack flow involves:

1. Identifying exposed iDRAC management interfaces on the network
2. Crafting malicious input data designed to overflow the vulnerable buffer
3. Sending the payload to the target iDRAC interface
4. Achieving either denial of service (crashing the iDRAC process) or arbitrary code execution

Successful exploitation enables complete control over the iDRAC management controller, which in turn provides hardware-level access to the server including power management, console access, and firmware modification capabilities. This makes the vulnerability particularly dangerous as it bypasses operating system security controls entirely.

Detection Methods for CVE-2020-5344

Indicators of Compromise

• Unexpected iDRAC service crashes or restarts indicating exploitation attempts
• Anomalous network traffic to iDRAC management ports (typically 443, 5900, 623)
• Unauthorized configuration changes to iDRAC settings or user accounts
• Suspicious processes or unexpected firmware modifications on iDRAC controllers

Detection Strategies

• Monitor iDRAC firmware versions across all Dell PowerEdge servers to identify vulnerable instances
• Implement network intrusion detection rules for malformed traffic targeting iDRAC services
• Enable and review iDRAC audit logs for authentication failures and unusual administrative actions
• Deploy network segmentation monitoring to detect unauthorized access to management networks

Monitoring Recommendations

• Configure SIEM rules to alert on iDRAC service availability issues or repeated connection attempts
• Establish baseline network behavior for iDRAC interfaces to identify anomalous traffic patterns
• Implement periodic firmware version auditing against known vulnerable versions
• Monitor for lateral movement attempts from compromised management networks

How to Mitigate CVE-2020-5344

Immediate Actions Required

• Update iDRAC7 firmware to version 2.65.65.65 or later immediately
• Update iDRAC8 firmware to version 2.70.70.70 or later immediately
• Update iDRAC9 firmware to version 4.00.00.00 or later immediately
• Isolate iDRAC management interfaces from untrusted networks until patching is complete

Patch Information

Dell has released firmware updates to address this vulnerability. Administrators should download and apply the latest iDRAC firmware from the Dell Security Advisory DSA-2020-063. The advisory provides detailed instructions for updating iDRAC firmware across all affected versions.

Workarounds

• Restrict network access to iDRAC interfaces using firewall rules to allow only trusted management networks
• Place all iDRAC controllers on isolated out-of-band management VLANs not accessible from production networks
• Implement VPN requirements for remote access to iDRAC management interfaces
• Disable unnecessary iDRAC services and ports to reduce the attack surface until patching can be completed

# Network isolation configuration example (firewall/ACL)
# Restrict iDRAC access to management network only
# Replace with your specific firewall syntax

# Allow management network access to iDRAC
iptables -A INPUT -s 10.0.100.0/24 -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -s 10.0.100.0/24 -p tcp --dport 5900 -j ACCEPT
iptables -A INPUT -s 10.0.100.0/24 -p udp --dport 623 -j ACCEPT

# Deny all other access to iDRAC ports
iptables -A INPUT -p tcp --dport 443 -j DROP
iptables -A INPUT -p tcp --dport 5900 -j DROP
iptables -A INPUT -p udp --dport 623 -j DROP