CVE-2024-37566: Infoblox NIOS Auth Bypass Vulnerability

CVE-2024-37566 Overview

CVE-2024-37566 is an improper authentication vulnerability affecting Infoblox NIOS through version 8.6.4. The flaw resides in the Grid functionality of NIOS, the operating system that powers Infoblox DDI (DNS, DHCP, IP address management) appliances. An unauthenticated attacker with network access to a vulnerable Grid can exploit weak authentication controls to compromise confidentiality, integrity, and availability of the system. The vulnerability is classified under CWE-284: Improper Access Control.

Critical Impact

Remote unauthenticated attackers can bypass authentication on Infoblox NIOS Grids, threatening core DNS, DHCP, and IPAM infrastructure.

Affected Products

• Infoblox NIOS versions up to and including 8.6.4
• Infoblox Grid deployments running affected NIOS releases
• Appliances managed through vulnerable Grid Master configurations

Discovery Timeline

• 2025-02-27 - CVE-2024-37566 published to NVD
• 2025-04-10 - Last updated in NVD database

Technical Details for CVE-2024-37566

Vulnerability Analysis

The vulnerability stems from improper authentication enforcement within the Infoblox NIOS Grid subsystem. NIOS Grids coordinate multiple Infoblox appliances as a single logical entity for DNS, DHCP, and IPAM services. Authentication weaknesses in this inter-node communication path allow attackers to interact with Grid functions without presenting valid credentials.

Because Infoblox appliances often serve as authoritative DNS and DHCP infrastructure, a compromise of the Grid carries downstream consequences. Attackers who reach the Grid network can manipulate DNS records, alter DHCP scopes, or extract sensitive network configuration data. The attack requires no user interaction and no prior privileges.

Root Cause

The root cause is improper access control on Grid communications, mapped to CWE-284. Authentication checks fail to adequately validate the identity of clients or peers interacting with the Grid. This allows unauthorized entities to invoke functionality that should require authenticated Grid membership or administrative credentials.

Attack Vector

The attack vector is network-based with low complexity. An attacker needs reachability to the Grid services exposed by an affected NIOS appliance. Once network access is established, the attacker can issue requests against the Grid interface that should be restricted to authenticated members. Successful exploitation can yield full read and write access to NIOS configuration data.

No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the Infoblox Support Article for vendor-supplied technical guidance.

Detection Methods for CVE-2024-37566

Indicators of Compromise

• Unexpected modifications to DNS records, DHCP reservations, or Grid member configurations on Infoblox appliances
• Authentication events on NIOS appliances originating from IP addresses outside expected Grid management ranges
• Unrecognized Grid join attempts or new Grid member registrations in NIOS audit logs

Detection Strategies

• Audit NIOS syslog and audit trail data for administrative actions that lack corresponding authenticated session records
• Compare current NIOS configuration baselines against known-good snapshots to identify unauthorized changes
• Inspect network flow data for connections to Infoblox Grid management ports from non-administrative subnets

Monitoring Recommendations

• Forward NIOS syslog data to a centralized SIEM and alert on configuration changes outside maintenance windows
• Enable continuous monitoring of DNS zone integrity using passive DNS and zone-transfer verification
• Track Grid Master and Grid Member health states for unexpected failovers or replication anomalies

How to Mitigate CVE-2024-37566

Immediate Actions Required

• Upgrade Infoblox NIOS to a fixed release as directed by the Infoblox Support Article
• Restrict network access to NIOS Grid management interfaces using firewall rules and dedicated management VLANs
• Rotate administrative credentials and API keys used with affected NIOS appliances after patching

Patch Information

Infoblox has issued guidance for affected NIOS versions through Infoblox Support Article 000010392. Customers should review the advisory for the specific fixed builds applicable to their NIOS release train and apply updates following Infoblox change-management procedures.

Workarounds

• Isolate Grid communication networks from general user and server networks using strict ACLs
• Disable or limit exposure of Grid services to only the IP addresses of legitimate Grid members
• Enforce VPN or jump-host access for any administrative interaction with NIOS appliances until patching is complete

# Configuration example: restrict Grid management access at the network edge
# Allow only designated management subnet to reach NIOS Grid ports
iptables -A INPUT -p tcp -s 10.10.10.0/24 --dport 1194 -j ACCEPT
iptables -A INPUT -p udp -s 10.10.10.0/24 --dport 1194 -j ACCEPT
iptables -A INPUT -p tcp --dport 1194 -j DROP
iptables -A INPUT -p udp --dport 1194 -j DROP