Content Delivery Network (CDN)
A Content Delivery Network (CDN) is a geographically distributed network of proxy servers and their data centers. Its fundamental purpose is to deliver web content to users faster by placing it on servers closer to their physical location. While primarily designed for performance and availability, CDNs play a significant role in cybersecurity by acting as a first line of defense against various online threats.
In the context of cybersecurity, here's how a CDN functions and contributes:
DDoS Mitigation: One of the most critical cybersecurity benefits of a CDN is its ability to absorb and mitigate Distributed Denial of Service (DDoS) attacks. Because a CDN has many servers spread across the globe, it can distribute incoming traffic across its vast network. When a DDoS attack occurs, the malicious traffic is dispersed and diluted across the CDN's infrastructure, preventing any single origin server from being overwhelmed. The CDN can filter out the bad traffic while allowing legitimate users to access the website.
Web Application Firewall (WAF) Integration: Many CDNs offer integrated Web Application Firewall (WAF) services. A WAF inspects HTTP/S traffic flowing to and from a web application, identifying and blocking common web vulnerabilities and attacks, such as SQL injection, cross-site scripting (XSS), and other OWASP Top 10 threats. By placing the WAF at the network's edge, before traffic reaches the origin server, CDNs can prevent malicious requests from ever reaching the application.
Bot Management: CDNs are often equipped with advanced bot management capabilities. They can identify and differentiate between legitimate bots (like search engine crawlers) and malicious bots (used for credential stuffing, scraping, spam, or vulnerability scanning). By blocking malicious bot activity, CDNs help protect websites from automated attacks that could compromise accounts, steal data, or degrade service.
SSL/TLS Termination and Management: CDNs can terminate SSL/TLS connections at the edge, closer to the user. This offloads the encryption/decryption burden from the origin server and ensures that data is encrypted in transit between the user and the CDN, and often between the CDN and the origin server as well. Many CDNs also offer free or low-cost SSL certificates, making it easier for websites to implement encryption and improve their security posture.
IP Masking and Origin Protection: By routing all traffic through the CDN, the actual IP address of the origin server is masked. This makes it more difficult for attackers to target the origin server directly, as they only see the CDN's IP addresses. This adds a layer of anonymity and protection for the backend infrastructure.
Reduced Attack Surface: Since the CDN serves cached content and filters malicious traffic, the exposed "attack surface” is significantly reduced. Attackers have fewer direct points of entry to exploit, as many requests are handled and secured at the CDN layer.
Caching and Performance as a Security Aid: While primarily for performance, caching static content at the CDN's edge means less traffic must hit the origin server. This reduces the strain on the server, making it more resilient to various attacks and ensuring continued availability even under moderate load.
A CDN acts as a powerful security perimeter, protecting web assets from a broad spectrum of cyber threats while enhancing performance and availability.
ThreatNG, as an all-in-one external attack surface management, digital risk protection, and security ratings solution, provides comprehensive capabilities that address organizations' cybersecurity challenges when using a Content Delivery Network (CDN).
ThreatNG's ability to perform purely external, unauthenticated discovery without connecting is a significant advantage when working with CDNs. A CDN masks the origin server's IP, making it difficult for attackers to target it directly. However, ThreatNG can still discover an organization's external footprint, including assets hidden behind the CDN. For example, ThreatNG's Domain Intelligence, specifically its DNS Intelligence capabilities, can uncover all DNS records, such as FQDNs and CNAMEs, that point to an organization's assets, regardless of whether they are served through a CDN. This ensures that ThreatNG can identify the associated domains and begin its assessment process even if a CDN is fronting a service. It can also identify forgotten or misconfigured subdomains that might bypass CDN protection for specific traffic types.
ThreatNG's detailed external assessment capabilities are crucial for evaluating the security posture of assets protected by a CDN:
Web Application Hijack Susceptibility: ThreatNG analyzes web applications' external attack surface. Even with a CDN providing a Web Application Firewall (WAF), ThreatNG can assess the underlying web application for vulnerabilities beyond the CDN's immediate protection layer, such as misconfigurations in the application code or unpatched software versions on the origin server.
Subdomain Takeover Susceptibility: This assessment uses external attack surface and digital risk intelligence, incorporating Domain Intelligence, to evaluate a website's subdomains, DNS records, and SSL certificate statuses. ThreatNG can identify dangling DNS records that point to deprovisioned services for organizations using a CDN, even if those records are managed within the CDN's DNS. If an organization forgets to remove a CNAME record from their CDN that points to an old, unused cloud service, ThreatNG would detect this as a potential subdomain takeover vulnerability.
BEC & Phishing Susceptibility: Derived from Domain Intelligence (including DNS Intelligence and Domain Name Permutations), this capability helps assess susceptibility to business email compromise and phishing. ThreatNG can identify look-alike domains that attackers might register to impersonate the organization, even if a CDN protects the legitimate domain. It also evaluates email security presence (DMARC, SPF, DKIM records), which are critical for email security and operate independently of a CDN's web traffic routing.
Data Leak Susceptibility: ThreatNG assesses Cloud and SaaS Exposure and Dark Web Presence. This is vital because while a CDN protects web traffic, sensitive data leaks can occur through misconfigured cloud storage buckets or exposed SaaS applications that the CDN does not directly protect. For instance, ThreatNG might find an open AWS S3 bucket associated with the organization that contains sensitive data, even if the primary website traffic flows through the CDN.
Cyber Risk Exposure: ThreatNG considers parameters such as certificates, subdomain headers, vulnerabilities, and sensitive ports. While a CDN might manage SSL/TLS certificates at the edge, ThreatNG can still detect issues with origin server certificates or identify sensitive ports exposed on the origin that are not routed through the CDN. It also factors in Code Secret Exposure, which discovers code repositories and sensitive data within them, often hosted outside the CDN's direct influence.
Mobile App Exposure: ThreatNG evaluates an organization's mobile apps' exposure by discovering them in marketplaces and analyzing their content for exposed access credentials, security credentials, and platform-specific identifiers. This goes beyond CDN protection, as mobile app vulnerabilities can exist in the application code or its direct connections, regardless of whether associated APIs are behind a CDN. For example, ThreatNG might discover a hardcoded API key within a mobile application that could be used to access a backend service, even if a CDN protects that service's public API.
ThreatNG provides various reports, including Executive, Technical, Prioritized (High, Medium, Low, and Informational), Security Ratings, Inventory, and Ransomware Susceptibility. These reports would offer organizations using a CDN a clear and prioritized view of risks identified across their external attack surface. For example, a report could highlight all vulnerable web applications or misconfigured DNS records found, along with their associated risk levels and actionable recommendations for remediation.
ThreatNG's continuous monitoring of the external attack surface, digital risk, and security ratings is essential for maintaining security with a CDN. Changes in DNS configurations, the accidental exposure of new services, or new vulnerabilities that emerge for existing technologies behind the CDN would be detected swiftly. If a new subdomain is provisioned and improperly secured, ThreatNG's continuous monitoring would quickly identify it, preventing it from becoming a long-term blind spot.
ThreatNG's investigation modules provide deep analytical capabilities:
Domain Intelligence: This includes DNS Intelligence (Domain Record Analysis, Domain Name Permutations, Web3 Domains). This allows organizations to thoroughly investigate all DNS records associated with their domains, even those managed by a CDN, to identify potential misconfigurations, abandoned records, or malicious permutations. An analyst could use DNS Intelligence to see if a seemingly legitimate domain has a CNAME record pointing to an untrusted third-party service, which could be a supply chain risk.
Sensitive Code Exposure: ThreatNG discovers public code repositories and uncovers digital risks such as exposed API keys and cloud credentials. This is vital for organizations using CDNs, as code repositories are often outside the CDN's direct protective scope. ThreatNG could identify a GitHub repository where an API key for a Cloudflare-protected service is accidentally committed, allowing an attacker to bypass the CDN's WAF.
Cloud and SaaS Exposure: This module identifies sanctioned and unsanctioned cloud services, impersonations, and open exposed cloud buckets. This is critical for organizations that use CDNs for their web presence but rely heavily on various cloud services and SaaS applications. ThreatNG might find an unsanctioned cloud storage instance or a publicly accessible SaaS dashboard, which could be a direct entry point for attackers, regardless of CDN protection.
Search Engine Exploitation: This module helps users investigate an organization’s susceptibility to exposing sensitive information via search engines. This includes identifying exposed errors, potential sensitive information, and susceptible files. While a CDN might serve content, search engines can still index misconfigured origin servers or exposed development environments. ThreatNG can discover these exposures, such as a development environment not adequately secured and inadvertently indexed by a search engine.
Intelligence Repositories (DarCache):
ThreatNG's DarCache repositories provide continuously updated intelligence, which is invaluable for organizations using CDNs:
Vulnerabilities (DarCache Vulnerability): This includes NVD, EPSS, KEV, and Verified Proof-of-Concept (PoC) Exploits. This intelligence helps organizations understand the real-world exploitability of vulnerabilities found on their assets, even those behind a CDN. For example, suppose ThreatNG identifies a vulnerability on an origin web server. In that case, DarCache will provide context on its exploitability (e.g., whether it's actively exploited in the wild via KEV ), allowing the organization to prioritize patching.
Dark Web (DarCache Dark Web) and Compromised Credentials (DarCache Rupture): These repositories track organizational mentions and compromised credentials. Even if a CDN secures the web perimeter, employee credentials could be compromised and found on the dark web. ThreatNG would alert the organization to these compromised credentials, which attackers could use to gain unauthorized access to internal systems, potentially bypassing CDN-level protections.
Complementary Solutions:
ThreatNG's capabilities can work synergistically with various other cybersecurity solutions to provide a more holistic security posture for organizations using CDNs:
Security Orchestration, Automation, and Response (SOAR) Platforms: ThreatNG's continuous monitoring alerts and detailed risk findings can be automatically ingested by SOAR platforms. For example, if ThreatNG identifies a new, critical vulnerability on a web application (even one behind a CDN), the SOAR platform could automatically create a ticket for the security team, pull additional context from other tools, and even initiate automated remediation steps, such as temporary blocking of traffic to the vulnerable path via the CDN's API.
Threat Intelligence Platforms (TIPs): ThreatNG's DarCache provides rich, updated threat intelligence, including ransomware groups, compromised credentials, and actively exploited vulnerabilities. This intelligence can augment a TIP, providing a more comprehensive view of the threat landscape relevant to the organization. For instance, if ThreatNG detects increased attacks by a specific ransomware group (via DarCache Ransomware ), this intelligence can be fed into a TIP, which can cross-reference it with other internal data to identify potentially targeted assets or users.
Cloud Security Posture Management (CSPM) Tools: While ThreatNG assesses cloud exposure from an external perspective, CSPM tools focus on cloud environments' internal configuration and compliance. Combining ThreatNG's external view (e.g., identifying publicly exposed cloud buckets ) with a CSPM's internal auditing can provide a complete picture of cloud security risks. ThreatNG might identify an inadvertently public S3 bucket, and a CSPM tool could then confirm internal misconfigurations and suggest remediation.
Vulnerability Management (VM) Systems: ThreatNG's external assessment and vulnerability intelligence (NVD, EPSS, KEV ) can enrich traditional VM systems. ThreatNG identifies externally exploitable vulnerabilities, complementing internal network scans. For example, if ThreatNG discovers a critical vulnerability on a web server that a CDN fronts, the VM system can then manage the patching process and track its remediation status alongside internally found vulnerabilities.
Digital Identity and Access Management (IAM) Solutions: ThreatNG's identification of compromised credentials on the dark web (DarCache Rupture ) can directly inform IAM solutions. When ThreatNG flags compromised credentials, the IAM system can be triggered to force password resets or implement multi-factor authentication for affected users, enhancing the organization's overall identity security.
