CVE intelligence and bounded remediation
CVE-2023-28112 — Discourse is an open-source discussion platform
Discourse is an open-source discussion platform. Prior to version 3.1.0.beta3 of the `beta` and `tests-passed` branches, some user provided URLs were being passed to FastImage without SSRF protection. Insufficient protections could enable attackers to trigger outbound network connections from the Discourse server to private IP addresses. This affects any site running the `tests-passed` or `beta` branches versions 3.1.0.beta2 and prior. This issue is patched in version 3.1.0.beta3 of the `beta` and `tests-passed` branches. There are no known workarounds.
- Severity
- High
- CVSS
- 8.1 (3.1)
- Published
- 2023-03-17
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-918
Affected products
- discourse / discourse
- discourse / discourse / 3.1.0
Matched remediation archetype
Server-side request forgery and unintended proxying
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
- Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
- Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.
Remediate safely
- Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
- Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
- Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.