EUVD-2026-65443
GHSA-7rwv-fqq2-88c4
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
PR:H reflects mandatory admin privileges; S:C because the vulnerable server initiates requests to out-of-scope internal systems; no availability impact.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
3DescriptionCVE.org
Ech0 through 4.2.1 contains a server-side request forgery vulnerability in the validateWebhookURL function (webhook_setting_service.go), which only validates literal IP addresses via net.ParseIP() and fails to reject hostnames that DNS-resolve to private or internal IPs (e.g., 169.254.169.254.nip.io). An attacker with admin privileges can create a webhook with such a hostname to bypass validation and cause the server to make requests to internal services, cloud metadata endpoints, and private network resources. The issue is fixed in 4.4.3.
AnalysisAI
Server-side request forgery in Ech0 through 4.2.1 (Go-based self-hosted application by lin-snow) allows an authenticated admin to exfiltrate data from internal network services and cloud metadata endpoints by exploiting a DNS resolution bypass in webhook URL validation. The validateWebhookURL function checks only literal IP strings via net.ParseIP(), so hostnames like 169.254.169.254.nip.io pass validation unchallenged and DNS-resolve to private IPs at request time. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires the attacker to hold admin-level privileges within Ech0 (CVSS PR:H), sufficient to call the webhook creation API (POST /api/webhook). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:H/UI:N) scores 5.1 (Medium), and the PR:H metric is the decisive limiting factor - exploitation is confined to users with admin-level access to the Ech0 instance. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An admin-level user authenticates to Ech0 and issues a POST /api/webhook request with a URL such as http://169.254.169.254.nip.io/latest/meta-data/iam/security-credentials/. The validateWebhookURL function passes the hostname through net.ParseIP(), receives nil, skips all private-IP checks, and stores the webhook as active. … |
| Remediation | Upgrade Ech0 to version 4.4.3 or later; this is the vendor-released patch confirmed by both the GitHub security advisory (GHSA-r2x7-427f-rq69) and VulnCheck. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-918 – Server-Side Request Forgery (SSRF)
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External POC / Exploit Code
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