## Critical SSRF Bypass Discovered: Empty DNS Resolution Arrays Can Evade Private IP Validation
A security researcher has identified and patched a Server-Side Request Forgery (SSRF) vulnerability in affected codebases. The flaw exploited how JavaScript's `dns.lookup()` function handles domain resolution when a maliciously crafted domain returns an empty address array. By supplying such a domain, an attacker could bypass IP validation checks designed to prevent requests to private, loopback, or internal network ranges.

The vulnerability resided in the validation logic that iterates through resolved IP addresses. When `dns.lookup` returned zero addresses, the subsequent loop that filters private and loopback IPs never executed, effectively whitelisting the domain without any security review. This allowed an attacker to potentially reach internal services, cloud metadata endpoints, or other protected infrastructure that should have been inaccessible from the public internet.

The fix implements a guard clause that explicitly handles empty DNS resolution results, ensuring the validation fails safely rather than silently passing. Security teams are advised to audit dependencies that perform DNS lookups prior to making outbound HTTP requests, particularly those handling user-supplied URLs or domains. This incident highlights how subtle edge cases in asynchronous API behavior can undermine seemingly robust security controls.
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- **Source**: GitHub Issues
- **Sector**: The Lab
- **Tags**: ssrf, security-vulnerability, dns-lookup, bypass, server-side-request-forgery
- **Credibility**: unverified
- **Published**: 2026-04-25 16:54:08
- **ID**: 77103
- **URL**: https://whisperx.ai/en/intel/77103