Description

OpenViking before 0.3.4 contains a server-side request forgery vulnerability that allows authenticated low-privilege attackers to access internal network services by submitting arbitrary URLs to the resources API endpoint. Attackers can POST a crafted URL to /api/v1/resources, causing the server to issue outbound HEAD and GET requests with redirects enabled to loopback, RFC 1918, link-local, or cloud metadata addresses, then read back responses through normal content APIs to enumerate and interact with internal services.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.5",
  "pubDate": "2026-08-21T16:17:16.767Z",
  "pubdate": "2026-08-21T16:17:16.767Z",
  "executiveSummary": "OpenViking before 0.3.4 contains a server-side request forgery vulnerability that enables authenticated low-privilege attackers to issue arbitrary outbound network requests and access internal network services.\nThe vulnerability resides in the resources API endpoint of the application, specifically through the processing of user-supplied URLs submitted via HTTP POST requests.\nBy leveraging this flaw, malicious actors can force the server to initiate HEAD and GET requests targeting loopback interfaces, RFC 1918 private address spaces, link-local ranges, and cloud metadata endpoints.\nSubsequent exploitation allows the retrieval of response data through standard content APIs, facilitating internal service enumeration and unauthorized interaction with protected infrastructure.\nThe risk implications include potential exposure of sensitive cloud metadata, internal network mapping, and unauthorized access to backend services otherwise shielded from external perimeters.\nSuccessful exploitation requires authenticated low-privilege access to the target system and the ability to interact with the resources API endpoint.",
  "technicalDetails": "The vulnerability is classified as a Server-Side Request Forgery (SSRF) flaw affecting OpenViking prior to version 0.3.4.\nThe vulnerable component is the resources API endpoint located at /api/v1/resources, which accepts arbitrary URLs submitted via HTTP POST requests.\nThe root cause stems from insufficient validation, sanitization, and restriction of destination Uniform Resource Locators supplied by users before the server initiates outbound network connections.\nAuthentication and low-privilege access are required prerequisites, as attackers must authenticate to the application and possess the baseline privileges needed to access the resources API endpoint.\nThe exploitation method involves an attacker crafting a malicious HTTP POST request directed at /api/v1/resources containing a target URL pointing to internal or restricted network destinations.\nUpon receiving the payload, the server processes the request and issues outbound HEAD and GET requests with HTTP redirects enabled.\nThe inclusion of redirects allows the request flow to bypass superficial URL checks and traverse into restricted network spaces, including loopback addresses (127.0.0.1/localhost), RFC 1918 private subnets, link-local addresses, and cloud provider metadata services.\nPost-exploitation impact and data retrieval occur when the server reads back the responses from the internal requests and exposes them to the user through normal content APIs.\nThis behavior permits attackers to enumerate internal services, probe listening ports behind the firewall, and extract sensitive operational data or cloud infrastructure secrets accessible via metadata endpoints."
}