Wildcard DNS Records
Wildcard DNS Records, in the context of security and cybersecurity, refer to a type of DNS record used to route requests for multiple subdomains under a specific domain to a shared location or IP address. These records are represented by an asterisk (*) symbol in the subdomain field and act as a catch-all for any subdomain that does not have a specific DNS record defined. While wildcard DNS records have legitimate uses, they can introduce security considerations:
Subdomain Enumeration: Wildcard DNS records sometimes make it easier for attackers to enumerate subdomains under a domain, as any random subdomain may resolve to the exact location. This gives attackers more information about an organization's digital assets and potentially aids in reconnaissance.
Phishing and Subdomain Takeover: Misconfigured wildcard DNS records can be exploited for phishing attacks or subdomain takeover vulnerabilities. Attackers can create arbitrary subdomains, potentially leading to impersonation of legitimate services and tricking users into providing sensitive information.
SSL Certificate Management: Wildcard DNS records often necessitate using wildcard SSL certificates covering multiple subdomains. Properly managing these certificates is essential to prevent unauthorized subdomain issuance, which can lead to man-in-the-middle attacks.
To ensure the secure use of wildcard DNS records, organizations should implement strict access controls, closely monitor their DNS configurations, and regularly review wildcard records to verify they are correctly configured and do not inadvertently expose security vulnerabilities. Properly managed wildcard DNS records can help simplify subdomain management while minimizing security risks.
How ThreatNG Helps with Wildcard DNS Record Risks
Superior Discovery: ThreatNG's Domain Intelligence module excels at uncovering subdomains, including those created by wildcard records. It uses various techniques, such as DNS intelligence, certificate intelligence, and domain name permutation analysis, to identify all possible subdomains associated with an organization. This helps eliminate blind spots created by wildcard records.
Subdomain Takeover Susceptibility: ThreatNG assesses explicitly the risk of subdomain takeover, a significant vulnerability associated with misconfigured wildcard records. By identifying vulnerable subdomains, organizations can proactively address them before attackers exploit them.
Continuous Monitoring: ThreatNG doesn't just perform a one-time scan. It monitors the attack surface for changes, including new subdomains that may appear due to wildcard records. This ensures that any new risks are identified and addressed promptly.
Deep and Dark Web Intelligence: ThreatNG's intelligence repositories scan the dark web for mentions of the organization's domain and subdomains, identifying potential malicious activity or compromised credentials related to wildcard record usage.
Working with Complementary Solutions
While ThreatNG offers comprehensive capabilities, it can be further enhanced by integrating with other security solutions:
Vulnerability Scanners: ThreatNG identifies vulnerabilities associated with wildcard records (e.g., exposed development environments, known CVEs). Integrating with vulnerability scanners like Nessus, Qualys, or OpenVAS allows for deeper inspection and validation of these findings.
Penetration Testing Tools: ThreatNG's findings can inform penetration testing efforts. Testers can use the identified subdomains and vulnerabilities to simulate attacks and assess the real-world impact of wildcard record misconfigurations.
Security Information and Event Management (SIEM): Integrating ThreatNG with a SIEM solution like Splunk or IBM QRadar allows for centralized logging and analysis of security events related to wildcard records and other external threats. This enables faster incident response and remediation.
Examples with Investigation Modules
Domain Intelligence: ThreatNG identifies a wildcard record pointing to an outdated web server. Using "Certificate Intelligence," it detects an expired SSL certificate, increasing the risk of man-in-the-middle attacks. The "Known Vulnerabilities" module flags the server as running a version of Apache with known exploits.
Sensitive Code Exposure: ThreatNG discovers a subdomain created through a wildcard record that unintentionally exposes a GitHub repository. The "Exposed Public Code Repositories" module identifies API keys and database credentials within the code, highlighting a critical security risk.
Dark Web Presence: ThreatNG's dark web intelligence module detects discussions about exploiting an organization-associated subdomain. This information allows the security team to proactively investigate and mitigate the potential threat before an attack occurs.
Archived Web Pages: ThreatNG discovers an archived web page on a forgotten subdomain created via a wildcard record. The page contains a login form for an outdated application with known vulnerabilities, presenting a potential entry point for attackers.
Key Takeaway
ThreatNG's comprehensive approach to EASM, DRP, and security ratings provides a powerful solution for managing the risks associated with wildcard DNS records. By combining superior discovery, continuous monitoring, and deep intelligence with integration capabilities, ThreatNG empowers organizations to proactively secure their external attack surface and minimize their exposure to cyber threats.
