Gitea: RSS/Atom feed handlers bypass API-token scope & public-only confinement (incomplete fix of #37698)
Summary
Gitea's RSS/Atom feed handlers accept API-token Basic auth but perform **no token-scope or
public-only enforcement**. A personal access token that is correctly blocked (HTTP 403) from a
private repository on /raw, /media, /archive, and /releases/download/... — because it is
marked *public-only* or lacks the repository scope category — still returns that repository's
private content through the feed routes. This is a token-confinement bypass and appears to be an
incomplete fix of #37698, which added that scope enforcement to the download handlers but not to the
sibling feed handlers.
This is not a cross-user access bug: the requesting account must still legitimately have repo
read access (RepoAssignment + reqUnitCodeReader are enforced). What is bypassed is the guarantee
that a *confined* token cannot reach private content — which is exactly the property #37698 was
shipped to provide for downloads, and which matters when such a token is handed to a third-party
service/CI, leaked, or used in a lower-trust integration.
Details
#37698 added context.CheckTokenScopes / CheckRepoScopedToken
(services/context/permission.go) to the raw / media / archive / attachment download handlers, so a
public-only or wrong-scope-category token cannot read private-repo content even when the owning user
otherwise has access.
The feed handlers are registered with webAuth.AllowBasic (so they accept token Basic auth) but call
no scope / public-only check. A grep for CheckTokenScopes / CheckRepoScopedToken / IsApiToken
across routers/web/feed/ and the release feed handlers returns nothing.
Affected routes (all token-reachable via webAuth.AllowBasic, none call the scope check):
| Route | Handler | Private data exposed |
|---|---|---|
| GET /{owner}/{repo}.rss / .atom | repo.Home → handleRepoHomeFeed (view_home.go) | last-10 commits: SHA, full message, author name + email |
| GET /{owner}/{repo}/rss/branch/*, /atom/branch/* | feed.RenderBranchFeed* → ShowBranchFeed (routers/web/feed/branch.go) | same commit data, any branch |
| GET /{owner}/{repo}/releases.rss / .atom | ReleasesFeedRSS/Atom (routers/web/repo/release.go) → ShowReleaseFeed | private release names, notes, descriptions |
| GET /{owner}/{repo}/tags.rss / .atom | TagsListFeedRSS/Atom → ShowReleaseFeed | private tag names + messages |
| GET /{user}.rss / .atom | showUserFeed (routers/web/feed/profile.go), includePrivate = self \|\| admin | the token owner's private cross-repo activity stream |
Inconsistency that pins this down: the branch-feed routes sit in the same route group as /raw,
/media, /archive (all of which call checkDownloadTokenScope), and releases.rss sits next to
/releases/attachments/{uuid} and /releases/download/... (both go through ServeAttachment → scope
check). Only the feeds were missed. The API equivalents (ListReleases / ListTags) are scope-gated
via tokenRequiresScopes.
Two distinct confinement bypasses:
1. Public-only bypass. A token created with the *public-only* option is blocked (403) from a
private repo on /raw, /archive, /releases/download/..., but returns private commit / release
data via .../releases.rss, .../rss/branch/*, /{owner}/{repo}.rss, and the owner's private
activity via /{user}.rss.
2. Scope-category bypass. A token scoped to only e.g. read:issue (no read:repository) is
rejected by the download handlers but reads repository commit/release content via the feeds.
PoC
Verified live against the official gitea/gitea:1.26.2 Docker image (sqlite, feeds enabled).
Setup: non-admin user alice; private repo alice/secret with a commit
"SECRET-COMMIT-MARKER ..." (file secret.txt) and a release "Private Release" / body
"SECRET-RELEASE-MARKER ...". Two confined personal access tokens, both sent via HTTP Basic so the
auth method is identical across download and feed — only the route differs:
- Token A: scopes
["public-only", "read:repository"] - Token B: scopes
["read:issue"]
```bash
# Token A — download is correctly blocked, feeds leak private content:
curl -u alice:$TOKEN_A https://<host>/alice/secret/raw/branch/main/secret.txt # => 403 (fix works)
curl -u alice:$TOKEN_A https://<host>/alice/secret/rss/branch/main # => 200, <title>SECRET-COMMIT-MARKER ...</title>
curl -u alice:$TOKEN_A https://<host>/alice/secret/releases.rss # => 200, SECRET-RELEASE-MARKER ...
curl -u alice:$TOKEN_A "https://<host>/alice.rss" # => 200, private activity
# Token B — wrong scope category, same split:
curl -u alice:$TOKEN_B https://<host>/alice/secret/raw/branch/main/secret.txt # => 403
curl -u alice:$TOKEN_B https://<host>/alice/secret/rss/branch/main # => 200, private commit leaked
```
Anonymous
