ApostropheCMS: Host header controls server-side image fetch origin in @apostrophecms/ai-helper, enabling authenticated SSRF

Why it is Yellow

• CVSS 4.3 medium
• Public exploit or proof of concept referenced
• On your watchlist: npm

Affected packages

References

• https://github.com/advisories/GHSA-527g-ff96-x6wj
• https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-527g-ff96-x6wj
• https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
• https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
• https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/ai-helper@1.0.0-beta.13
• https://github.com/advisories/GHSA-527g-ff96-x6wj

Original description

ApostropheCMS is an open-source Node.js content management system. From 1.0.0-beta.10 until 1.0.0-beta.13 of the AI helper, an editor with image-generation capability can create a base64-generated image record without a stored provider URL and invoke image acceptance on a deployment using local relative storage with no trusted global base URL. The server resolves the fixed uploads path against a request-controlled Host-derived origin, enabling bounded server-side requests to an attacker-selected host, port, and HTTP origin, but not arbitrary-path retrieval or the stored-provider and absolute-storage configurations. This issue is fixed in AI helper 1.0.0-beta.13.