Backport #38406 by @bircni
Addresses a batch of privately reported security issues, grouped by
area:
- **SSRF** - migration PR-patch/asset fetches, OAuth2 avatar & OpenID
discovery, pull-mirror URL re-validation, and the outbound proxy path.
- **Access-token scope** - prevent scope escalation on token creation;
keep public-only tokens confined (feeds, packages, Actions listings,
star/watch lists, limited/private owners).
- **Access control / disclosure** - go-get default-branch leak, webhook
authorization-header leak, watch clearing on private transitions,
label/attachment scoping.
- **Denial of service** - input bounds for npm dist-tags, Debian control
files, Arch file lists, and SSH keys.
### 📌 Attention for site admins
Not breaking - existing configs keep working - but two changes are worth
a look:
- **New SSRF protection** Outbound requests (migrations, OAuth2 avatars,
OpenID discovery, pull mirrors, proxy path) are now validated against
the allow/block host lists. If your instance legitimately reaches
internal hosts, you may need to add them to
`[security].ALLOWED_HOST_LIST` (and the relevant `ALLOW_LOCALNETWORKS`
settings).
- **Deprecation** `[webhook].ALLOWED_HOST_LIST` is deprecated and will
be removed in a future release. Use `[security].ALLOWED_HOST_LIST`
instead; the old key still works for now.
Co-authored-by: bircni <bircni@icloud.com>
Co-authored-by: TheFox0x7 <thefox0x7@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Zettat123 <zettat123@gmail.com>
## Summary
Fixes
[go-gitea/gitea#37564](https://github.com/go-gitea/gitea/issues/37564):
when an OIDC provider returns a `picture` claim, Gitea is supposed to
download that image as the user's avatar (if `[oauth2_client]
UPDATE_AVATAR = true`). Two latent bugs prevented this from working
consistently:
1. **Default Go User-Agent rejected by some image hosts.**
`oauth2UpdateAvatarIfNeed` used `http.Get`, which sends `User-Agent:
Go-http-client/1.1`. Hosts like `upload.wikimedia.org` reject that UA
with `403`, and every error path silently returned, so the user was left
with an identicon and **no log line** to diagnose the issue.
2. **Link-account *register* path skipped avatar sync.** First-time OIDC
sign-ins where auto-registration is disabled (or required a
username/password retype) go through `LinkAccountPostRegister`, which
created the user but never called `oauth2SignInSync`. So the avatar /
full name / SSH keys from the IdP were dropped on the floor for those
users, even though the existing-account-link path (`oauth2LinkAccount`)
and the auto-register path (`handleOAuth2SignIn`) both already did the
sync.
## Changes
- `routers/web/auth/oauth.go` — `oauth2UpdateAvatarIfNeed` now uses
`http.NewRequest` + `http.DefaultClient.Do`, sets `User-Agent: Gitea
<version>`, and logs every failure path at `Warn` (invalid URL, fetch
error, non-200, body read error, oversize body, upload error). No silent
failures.
- `routers/web/auth/linkaccount.go` — `LinkAccountPostRegister` now
calls `oauth2SignInSync` after a successful user creation, mirroring the
auto-register and link-existing-account flows.
- `tests/integration/oauth_avatar_test.go` — new
`TestOAuth2AvatarFromPicture` integration test with five sub-cases:
- `AutoRegister_FetchesAvatarFromPictureWithGiteaUA` — happy path,
asserts `use_custom_avatar=true`, an avatar hash is set, exactly one
HTTP request was made, and the request carried a `Gitea ` UA. The mock
server enforces the UA prefix to mirror real-world hosts that reject
Go's default UA.
- `AutoRegister_NonOK_DoesNotUpdateAvatar` — server returns 403; user's
avatar must remain unset.
- `AutoRegister_EmptyPicture_NoFetch` — empty `picture` claim must not
trigger any HTTP request.
- `AutoRegister_UpdateAvatarFalse_NoFetch` — `UPDATE_AVATAR=false` must
not trigger any HTTP request.
- `LinkAccountRegister_FetchesAvatarFromPicture` — guards the
`linkaccount.go` fix; without the new `oauth2SignInSync` call this
assertion fails.
## Related
- Upstream issue: go-gitea/gitea#37564
--------------------------------------------
AI Editor was used in this PR
---------
Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Nicolas <bircni@icloud.com>
Giteabot