GHSA-c66c-vq6w-fvh5 Omni: Operator can traverse image-factory API paths via unsanitized `talos_version` in CreateSchematic

• Go github.com/siderolabs/omni: < 1.6.6 → fixed in 1.6.6 • Go github.com/siderolabs/omni: >= 1.7.0, < 1.7.3 → fixed in 1.7.3

Summary `managementServer.CreateSchematic` (`internal/backend/grpc/schematics.go`) passes the caller-controlled `TalosVersion` field directly to `imageFactoryClient.OverlaysVersions`, which embeds it verbatim into a `fmt.Sprintf("/version/%s/overlays/official", talosVersion)` path template. `url.URL.JoinPath` resolves any `../` sequences in that path, allowing an authenticated Operator to rewrite the URL path and force Omni to issue HTTP GET requests to unintended paths on the configured image-factory server. Error body content from those unintended endpoints is returned to the caller. Severity • Attack Vector: Network: exploited via the gRPC `CreateSchematic` API endpoint. • Attack Complexity: Low: once the attacker holds an Operator credential and has identified a media ID with an overlay, exploitation is a single API call. • Privileges Required: High: `role.Operator` is required, which has administrative capabilities on Omni. • User Interaction: None. • Scope: Unchanged: the traversal is constrained to the configured image-factory host; the attacker cannot redirect Omni to an arbitrary external server. • Confidentiality Impact: Low: error body content from unintended image-factory endpoints is reflected back to the operator, potentially leaking server-internal information. • Integrity Impact: None: only HTTP GET requests are issued; no write operations are performed. • Availability Impact: None. Impact • Same-host path traversal: An authenticated Operator can force Omni to issue GET requests to arbitrary URL paths on the configured image-factory server, bypassing the intended versioned overlay API structure. • Error-body disclosure: HTTP error responses from unintended image-factory endpoints are reflected back to the operator, potentially leaking server-internal diagnostics or sensitive path content. • Internal network probing: In deployments using a private image-factory instance on an internal network, the attacker can probe endpoint existence and partial responses through error-text differences. • Depth control: By varying the number of `../` prefixes in `talosVersion`, the attacker can reach any path hierarchy on the image-factory host. Credit This vulnerability was discovered and reported by bugbunny.ai.