A Dangling DNS record, like a forgotten CNAME to an expired AWS S3 bucket under example.com, lingers in your Zone file after decommissioning a service. Is it a harmless relic, or a primed Subdomain takeover vector inviting phishing or malware hosting? Manual audits can miss these, exposing your Attack Surface.
The Dangling DNS view scans a Domain to reveal obsolete or misconfigured records pointing to non-existent resources, flagging risks like subdomain takeovers in Total View. It outputs counts and details on exploitable entries, such as unresolved A records or dangling MX pointers, drawing from Silent Push’s exhaustive DNS enumeration to highlight threats before adversaries exploit them.
Dangling records serve as backdoors, allowing attackers to hijack them for traffic redirection, cookie poisoning, or impersonation, as seen in real-world breaches where obsolete CNAMEs led to unauthorized access to corporate networks. It delivers instant appraisals of exposure scale, uncovering hidden vulnerabilities such as 2,000+ dangling entries in a single healthcare firm's scan, preventing exploits, and automating ongoing hygiene for proactive defense. Teams correlate findings with third-party service scans to audit forgotten integrations, essential for compliance audits or pre-merger due diligence in defender operations.
How It Works
The aggregation engine probes the global DNS for misconfigurations, identifying records tied to de-provisioned IPs, servers, or cloud assets that third parties do not update. Core outputs include counts for scope and details for triage; the view flags state, such as expired or unresolved, with exportable data for control panel fixes.
It links across views: A dangling CNAME might align with PADNS lapses, signaling potential takeover, while feeding into Total View for enriched context, such as associated subdomains.
Generate a Set of Results
Input an apex domain (e.g., example.com) in the search bar to open Total View, then click the Dangling DNS view. Results load with counts and lists. You can filter by record type (e.g., CNAME only) or state, and toggle subdomain views for nested risks.
Example
Query paypal.com in Dangling DNS: Records Count shows 12 dangling CNAMEs (with 0 NS and 1 MX), totaling 13 results. The bar chart highlights the CNAME spike in yellow, against baselines of unchanged (blue) and added/removed (green/orange) danglers.
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Details expand to reveal entries, such as cloudmonitor14.paypal.com, which is a CNAME to cloudmonitor14c6c8.edgecastdns.net (external, unchanged state), tied to a subdomain at risk for takeover. Another flags leovip.paypal.com as an internal CNAME loop (unchanged), with a risk score peaking at medium for misconfiguration exploits.
Hover for notes: The description warns of potential traffic interception via hijacked Edgecast resources.
Fields
Records Count: The total number of dangling DNS records detected for the apex domain (e.g., 13), indicating the scale of exposure for cleanup prioritization. A spike suggests widespread misconfiguration due to rapid de-provisioning.
Record Type: The DNS entry category (e.g., A, CNAME, MX), with counts per type to focus on takeover-prone ones like dangling CNAMEs to SaaS providers.
State: The vulnerability status (e.g., unresolved, expired, de-provisioned), indicating exploit readiness—e.g., an expired A record to a nuked IP.
Dangling DNS View
The details view logs specific records with granular attributes for remediation. For clean domains like test.com, it may return zero counts.
It includes subdomain names (e.g., dev.example.com), full record strings, associated IP addresses and services, and risk flags.
Hover entries for expanded information: Exploit paths, update timestamps, and pivot links to external validators.
Use Case
Remediate subdomain takeovers, such as CNAME records pointing to forgotten Azure blobs, which are exploited for credential theft.
Work with Dangling DNS Results
Dangling DNS enables CSV exports for DNS panel bulk edits, one-click pivots to Live Scans for current resolutions, and scheduling automated queries (e.g., daily runs). Customize views (e.g., add third-party service columns), save high-risk lists to Draft Feeds for monitoring, or integrate with a SIEM to alert on new dangling issues.