CVE-2022-0667: ISC BIND DOS Vulnerability

CVE-2022-0667 Overview

CVE-2022-0667 is a Denial of Service vulnerability affecting ISC BIND 9.18.0 that causes the BIND process to exit unexpectedly when triggered. This vulnerability is classified as CWE-617 (Reachable Assertion), where an assertion failure in the DNS server software leads to service termination. The flaw allows remote attackers to disrupt DNS resolution services without requiring authentication, potentially causing significant network outages for organizations relying on affected BIND installations.

Critical Impact

Remote attackers can crash BIND DNS servers without authentication, causing complete denial of DNS resolution services and potential widespread network disruption.

Affected Products

• ISC BIND 9.18.0
• NetApp H300S, H500S, H700S (Storage Systems with affected firmware)
• NetApp H300E, H500E, H700E (Storage Systems with affected firmware)
• NetApp H410S, H410C (Storage Systems with affected firmware)

Discovery Timeline

• March 22, 2022 - CVE-2022-0667 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-0667

Vulnerability Analysis

This vulnerability stems from a reachable assertion condition (CWE-617) within ISC BIND 9.18.0. The flaw allows an attacker to trigger an assertion failure that causes the named daemon to terminate unexpectedly. When the vulnerable code path is reached under specific conditions, the assertion check fails, invoking the abort mechanism and crashing the BIND process entirely.

The impact is focused on availability, with no direct effect on confidentiality or integrity of data. However, the denial of service can have cascading effects across network infrastructure, as DNS resolution is a critical service for virtually all network-connected applications and services.

Root Cause

The root cause is an improperly handled assertion condition in the BIND 9.18.0 codebase. Assertions are typically used during development to catch programming errors, but in this case, the assertion can be triggered through normal operation under specific circumstances. When the assertion fails, the BIND process calls abort(), resulting in immediate process termination rather than graceful error handling.

Attack Vector

The attack can be executed remotely over the network without requiring authentication or user interaction. An attacker with network access to a vulnerable BIND server can send specially crafted DNS queries or trigger specific conditions that cause the assertion to fail. This low complexity attack makes it particularly dangerous for internet-facing DNS servers.

The vulnerability mechanism involves triggering an internal state that violates an expected condition in the code. When the BIND process encounters this unexpected state, the assertion check fails, and the process exits immediately. The simplicity of exploitation—requiring only network access and no special privileges—increases the risk for organizations running affected versions.

Detection Methods for CVE-2022-0667

Indicators of Compromise

• Unexpected BIND/named process terminations or restarts in system logs
• Core dump files generated by the named daemon with assertion failure signatures
• DNS resolution failures coinciding with BIND process crashes
• Log entries containing "assertion failure" or similar error messages from named

Detection Strategies

• Monitor system logs for named process crashes and assertion failure messages
• Implement process monitoring to detect unexpected BIND daemon restarts
• Configure alerting for DNS service availability using synthetic monitoring
• Review core dump analysis for patterns consistent with assertion failures

Monitoring Recommendations

• Enable detailed logging in BIND configuration to capture diagnostic information
• Deploy DNS query logging to correlate crashes with specific query patterns
• Implement service health checks that detect DNS resolution failures
• Use SentinelOne's endpoint detection capabilities to monitor for process anomalies and unexpected terminations

How to Mitigate CVE-2022-0667

Immediate Actions Required

• Identify all BIND 9.18.0 installations in your environment immediately
• Review the ISC CVE-2022-0667 Advisory for vendor-specific guidance
• Plan and schedule emergency patching for internet-facing DNS servers
• Consider implementing DNS service redundancy to minimize impact during patching

Patch Information

ISC has released patches addressing this vulnerability. Organizations should upgrade from BIND 9.18.0 to a patched version as recommended by ISC. Consult the ISC Knowledge Base for specific version recommendations and upgrade procedures.

For NetApp products, refer to the NetApp Security Advisory NTAP-20220408-0001 for firmware update information and affected product details.

Workarounds

• Deploy redundant DNS infrastructure to maintain availability during attacks
• Implement rate limiting on DNS queries to reduce attack surface
• Use network-level filtering to restrict DNS access to trusted sources where possible
• Consider deploying DNS servers behind a protective proxy or load balancer with health checking

# Configuration example - Enable query logging for detection
# Add to named.conf to monitor for suspicious activity
logging {
    channel query_log {
        file "/var/log/named/query.log" versions 3 size 10m;
        severity info;
        print-time yes;
    };
    category queries { query_log; };
};