{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/ech0--1.4.8-0.20260503040602-091d26d2d942/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["ech0 (\u003c 1.4.8-0.20260503040602-091d26d2d942)"],"_cs_severities":["high"],"_cs_tags":["ssrf","ech0","github"],"_cs_type":"advisory","_cs_vendors":["GitHub"],"content_html":"\u003cp\u003eEch0, a service developed by lin-snow, is susceptible to a Server-Side Request Forgery (SSRF) vulnerability. The vulnerability lies in the \u003ccode\u003efetchPeerConnectInfo\u003c/code\u003e function (\u003ccode\u003einternal/service/connect/connect.go\u003c/code\u003e) where \u003ccode\u003ehttpUtil.SendRequest\u003c/code\u003e is used instead of \u003ccode\u003eSendSafeRequest\u003c/code\u003e. This oversight allows authenticated users to craft connections to internal or external services, leading to unauthorized information disclosure. Specifically, attackers can target internal services, cloud metadata endpoints like AWS IMDSv1 (169.254.169.254), GCE metadata, and the Kubernetes API (kubernetes.default.svc.cluster.local). The affected version is any version of ech0 prior to commit \u003ccode\u003e1.4.8-0.20260503040602-091d26d2d942\u003c/code\u003e. This vulnerability was reported on May 7, 2026.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker authenticates to the Ech0 service.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious POST request to \u003ccode\u003e/api/connects\u003c/code\u003e to add a new connection.\u003c/li\u003e\n\u003cli\u003eIn the POST request, the \u003ccode\u003econnect_url\u003c/code\u003e field is set to a URL pointing to an internal resource, such as \u003ccode\u003ehttp://169.254.169.254/latest/meta-data/instance-id\u003c/code\u003e (AWS metadata service) or \u003ccode\u003ehttp://kubernetes.default.svc.cluster.local:443/api\u003c/code\u003e (Kubernetes API).\u003c/li\u003e\n\u003cli\u003eThe Ech0 server receives the POST request and stores the malicious \u003ccode\u003econnect_url\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe attacker triggers a health check on the newly created connection via a request to \u003ccode\u003e/api/connects/health\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003efetchPeerConnectInfo\u003c/code\u003e function is called with the attacker-controlled URL.\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003ehttpUtil.SendRequest\u003c/code\u003e makes an HTTP request to the specified internal resource without proper validation.\u003c/li\u003e\n\u003cli\u003eThe response from the internal resource is returned to the attacker, potentially revealing sensitive information.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this SSRF vulnerability allows an attacker to access sensitive internal resources that are normally protected. This includes cloud metadata, such as AWS EC2 instance IDs, IAM roles, and other configuration details. Access to the Kubernetes API could allow for further lateral movement and privilege escalation within the Kubernetes cluster. The number of potential victims is dependent on the deployment scale and network architecture of Ech0 instances, but all authenticated users could potentially trigger the vulnerability.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the patch or upgrade to a version of Ech0 that includes the fix for this vulnerability (\u003ccode\u003e\u0026gt;= 1.4.8-0.20260503040602-091d26d2d942\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Ech0 SSRF via Connection to Metadata Endpoint\u003c/code\u003e to identify attempts to exploit this vulnerability by detecting connections to common cloud metadata endpoints.\u003c/li\u003e\n\u003cli\u003eMonitor network connections for outbound traffic originating from the Ech0 server to internal IP addresses or domains, specifically \u003ccode\u003e169.254.169.254\u003c/code\u003e and \u003ccode\u003ekubernetes.default.svc.cluster.local\u003c/code\u003e, as listed in the IOCs table.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-02T10:00:00Z","date_published":"2024-01-02T10:00:00Z","id":"/briefs/2024-01-ech0-ssrf/","summary":"Ech0 is vulnerable to Server-Side Request Forgery (SSRF) via the `fetchPeerConnectInfo` function, which uses `httpUtil.SendRequest` without SSRF protection, allowing authenticated users to make the server request arbitrary URLs, including internal/cloud metadata endpoints.","title":"Ech0 Server-Side Request Forgery (SSRF) Vulnerability","url":"https://feed.craftedsignal.io/briefs/2024-01-ech0-ssrf/"}],"language":"en","title":"CraftedSignal Threat Feed — Ech0 (\u003c 1.4.8-0.20260503040602-091d26d2d942)","version":"https://jsonfeed.org/version/1.1"}