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SSRF in Webhooks

High
caarlos0 published GHSA-vwq2-jx9q-9h9f Nov 10, 2025

Package

gomod github.com/charmbracelet/soft-serve (Go)

Affected versions

< v0.11.0

Patched versions

v0.11.1

Description

SUMMARY

We have identified and verified an SSRF vulnerability where webhook
URLs are not validated, allowing repository administrators to create
webhooks targeting internal services, private networks, and cloud
metadata endpoints.

AFFECTED COMPONENTS (VERIFIED)

  1. Webhook Creation (pkg/ssh/cmd/webhooks.go:125)
  2. Backend CreateWebhook (pkg/backend/webhooks.go:17)
  3. Backend UpdateWebhook (pkg/backend/webhooks.go:122)
  4. Webhook Delivery (pkg/webhook/webhook.go:97)

IMPACT

This vulnerability allows repository administrators to perform SSRF
attacks, potentially enabling:

a) Cloud Metadata Theft - Access AWS/Azure/GCP credentials via
169.254.169.254
b) Internal Network Access - Target localhost and private networks
(10.x, 192.168.x, 172.16.x)
c) Port Scanning - Enumerate internal services via response codes and
timing
d) Data Exfiltration - Full HTTP responses stored in webhook delivery
logs
e) Internal API Access - Call internal admin panels and Kubernetes
endpoints

PROOF OF CONCEPT

Simple example demonstrating localhost access:

ssh localhost webhook create my-repo http://127.0.0.1:8080/internal \
    --events push --active

then push to trigger.

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

CVE ID

CVE-2025-64522

Weaknesses

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Learn more on MITRE.

Credits