---
id: "bug-1952"
status: "fixed"
status_updated: "2026-10-10"
status_note: ""
component: "apiserver"
severity: "security"
timestamp: "2026-10-10T08:15:16Z"
last_seen: "2026-10-10T08:15:16Z"
occurrences: 1
files: ["src/frontend/apiserver/controllers/users.go"]
tags: ["apiserver", "security", "rbac"]
related: []
fix_commits: ["a80768f3"]
gitea_issue: 383
gitea_synced_status: "fixed"
gitea_synced_hash: "d6676e7948f8"
---

# bug-1952: apiserver user role changes check a narrower rbac:control grant only against the target user

## Description
**Observed:** (source reading, `.kiro/reviews/project-gap-review-2026-10-10.md` (P0); to be confirmed by a failing test before the fix)
Suspected (needs verification): in add/delete roles for a user, a non-`all` `rbac:control` grant is only checked against "is the target me?" (`controllers/users.go:404-412,455-462`), so such a grant could let a user give itself `cluster_admin`. Built-in roles grant `rbac:control` only with domain `all` (`config/rbac.yaml:100-102`), so this is latent.

**Expected:** A user can never grant itself a role with more rights than it already holds.
**Impact:** Security (latent): privilege escalation through a custom role.
**Found by:** review: `.kiro/reviews/project-gap-review-2026-10-10.md` (P0)
## Environment
- OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
- libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2)
- Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
- Build: asan (xce.build)
- Code: scheduler-framework @ 94472ee3-dirty
- Deployment: any (found by source reading; the failing test that confirms it is named in Verification)

## Reproduction
1. Define a role with `rbac:control` scoped to `self`, assign it to a user, then add `cluster_admin` to that same user via the users API.
- Frequency: deterministic (by code reading; confirmed by the RED test of the fix)
- Evidence: the code sites quoted in Description; no logs kept.
## Root cause
`UserController.AddRolesForUser`/`DeleteRolesForUser` (`controllers/users.go`) only checked whether the target was the caller for a non-`all` `rbac:control` grant; `self` is an accepted rbac scope (`models/roles.go:78`), so a user holding only `rbac:control` scope `self` could grant itself `cluster_admin`.

## Fix
`canChangeUserRoles`: changing anyone's roles (the caller's included) requires an `rbac:control` grant with scope `all`, checked over all grants before deduplication; anything else gets 403. Follow-up: any `rbac:control` scope can still create roles and add permissions to a role the caller holds (`roles.go`), the same escalation by another route.

## Verification
- Test: `TestAddRolesForUser_SelfScopeCannotGrantItselfRoles` (`controllers/users_rbac_test.go`): RED `privilege escalation: mallory (rbac:control scope self) granted itself cluster_admin (status 200)`, GREEN after; plus `TestDeleteRolesForUser_SelfScopeRejected`, `TestUserRoleChanges_AllScopeAllowed`.
- Suites: `xce-build.sh all asan xce.build --incremental` on the merged branch, 2026-10-10: all C suites Ok 155 / Fail 0, frontend Go unit tests ok, xceadmin tests ok; apiserver `CGO_ENABLED=0 go test ./...` (incl. middleware, router, cmd) ok
- Live: n/a: unit/fixture-level verification only; no live deployment was run (follow-up)

## References
- Fix commit: `a80768f3` (on `scheduler-framework`; worker-branch original in the merge)
- Review: `.kiro/reviews/project-gap-review-2026-10-10.md`