References to Advisories, Solutions, and Tools

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Change History

Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy fetches metadata for user-supplied post URLs and, under the default StoreLinkPreviews image mode, downloads the preview image through local pict-rs. While the top-level page URL is checked against internal IP ranges, the extracted og:image URL is not subject to the same restriction. As a result, an authenticated low-privileged user can submit an attacker-controlled public page whose Open Graph image points to an internal image endpoint. Lemmy will fetch that internal image server-side and store a local thumbnail that can then be served back to users. This issue has been patched in version 0.19.18.

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CWE-918

https://github.com/LemmyNet/lemmy/releases/tag/0.19.18

https://github.com/LemmyNet/lemmy/security/advisories/GHSA-h6hf-9846-xwrq