From 12677a928dd494baf2f6fb7679ff63b69943a77b Mon Sep 17 00:00:00 2001
From: Jason Woltje <jason.woltje@uscllc.com>
Date: Sun, 9 Aug 2026 00:28:57 -0500
Subject: [PATCH] fix(mosaic): prevent init prompt code execution

---
 .../framework/tools/_scripts/mosaic-init      |  8 +++----
 .../tools/_scripts/test-mosaic-init-rce.sh    | 21 +++++++++++++++++++
 packages/mosaic/package.json                  |  2 +-
 3 files changed, 26 insertions(+), 5 deletions(-)
 create mode 100644 packages/mosaic/framework/tools/_scripts/test-mosaic-init-rce.sh

diff --git a/packages/mosaic/framework/tools/_scripts/mosaic-init b/packages/mosaic/framework/tools/_scripts/mosaic-init
index 08830f9a..7dc20748 100755
--- a/packages/mosaic/framework/tools/_scripts/mosaic-init
+++ b/packages/mosaic/framework/tools/_scripts/mosaic-init
@@ -99,7 +99,7 @@ prompt_if_empty() {
 
   if [[ $NON_INTERACTIVE -eq 1 ]]; then
     if [[ -n "$default_value" ]]; then
-      eval "$var_name=\"$default_value\""
+      printf -v "$var_name" %s "$default_value"
       return
     fi
     echo "[mosaic-init] ERROR: --$var_name is required in non-interactive mode" >&2
@@ -115,7 +115,7 @@ prompt_if_empty() {
   if [[ -z "$value" && -n "$default_value" ]]; then
     value="$default_value"
   fi
-  eval "$var_name=\"$value\""
+  printf -v "$var_name" %s "$value"
 }
 
 prompt_multiline() {
@@ -129,7 +129,7 @@ prompt_multiline() {
   fi
 
   if [[ $NON_INTERACTIVE -eq 1 ]]; then
-    eval "$var_name=\"$default_value\""
+    printf -v "$var_name" %s "$default_value"
     return
   fi
 
@@ -139,7 +139,7 @@ prompt_multiline() {
   if [[ -z "$value" ]]; then
     value="$default_value"
   fi
-  eval "$var_name=\"$value\""
+  printf -v "$var_name" %s "$value"
 }
 
 # ── Existing file detection ────────────────────────────────────
diff --git a/packages/mosaic/framework/tools/_scripts/test-mosaic-init-rce.sh b/packages/mosaic/framework/tools/_scripts/test-mosaic-init-rce.sh
new file mode 100644
index 00000000..ed40f3b3
--- /dev/null
+++ b/packages/mosaic/framework/tools/_scripts/test-mosaic-init-rce.sh
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Source only the prompt helpers; executing mosaic-init itself requires templates.
+source <(head -n 144 "$(dirname "$0")/mosaic-init")
+
+rm -f /tmp/pwned
+payload='literal "$(touch /tmp/pwned)"'
+AGENT_NAME=""
+prompt_if_empty AGENT_NAME "Agent name" <<<"$payload"
+
+[[ "$AGENT_NAME" == "$payload" ]] || {
+  echo "FAIL: prompt answer did not round-trip literally" >&2
+  exit 1
+}
+[[ ! -e /tmp/pwned ]] || {
+  echo "FAIL: prompt answer executed code" >&2
+  rm -f /tmp/pwned
+  exit 1
+}
+echo "mosaic-init RCE regression: PASS"
diff --git a/packages/mosaic/package.json b/packages/mosaic/package.json
index 5daa5d06..b94e865e 100644
--- a/packages/mosaic/package.json
+++ b/packages/mosaic/package.json
@@ -25,7 +25,7 @@
     "lint": "eslint src",
     "typecheck": "tsc --noEmit",
     "test": "vitest run --passWithNoTests && pnpm run test:framework-shell",
-    "test:framework-shell": "bash framework/tools/quality/scripts/check-test-enumeration.sh && bash framework/tools/quality/scripts/test-check-test-enumeration.sh && python3 src/lease-broker/daemon_deadline_unittest.py && python3 src/lease-broker/normative_fragments_unittest.py && python3 src/lease-broker/receipt_challenge_unittest.py && python3 src/lease-broker/context_recovery_unittest.py && python3 src/lease-broker/recovery_runtime_unittest.py && python3 src/lease-broker/recovery_b1_adversarial_unittest.py && python3 src/lease-broker/framework_skill_portability_unittest.py && python3 src/mutator-gate/runtime_tools_unittest.py && python3 src/mutator-gate/runtime_launch_guard_unittest.py && python3 src/mutator-gate/version_coupling_unittest.py && python3 framework/tools/lease-broker/check-runtime-launches.py --root ../.. && bash framework/tools/codex/test-pr-diff-context.sh && bash framework/tools/qa/test-deps-preflight.sh && bash framework/tools/git/test-pr-review-gitea-comment.sh && bash framework/tools/git/test-pr-review-repo-host-override.sh && bash framework/tools/git/test-ci-queue-wait-branch-absent.sh && bash framework/tools/git/test-ci-queue-wait-tristate.sh && bash framework/tools/git/test-ci-queue-wait-github-checks.sh && bash framework/tools/git/test-pr-merge-queue-branch.sh && bash framework/tools/git/test-pr-merge-head-pin.sh && bash framework/tools/git/test-git-credential-mosaic.sh && bash framework/tools/git/test-gitea-token-identity.sh && bash framework/tools/woodpecker/test-terminal-green-contract.sh && bash framework/tools/_scripts/test-install-ordering-guard.sh && bash framework/tools/tmux/agent-send.test.sh && bash framework/tools/wake/test-wake-store-ack.sh && bash framework/tools/wake/test-wake-store-enqueue-race.sh && bash framework/tools/wake/test-wake-digest-hmac.sh && bash framework/tools/wake/test-wake-digest-quarantine.sh && bash framework/tools/wake/test-wake-detector.sh && bash framework/tools/wake/test-wake-fn-oracle.sh && bash framework/tools/wake/test-wake-reconcile.sh && bash framework/tools/wake/test-wake-beacon.sh && bash framework/tools/wake/test-wake-preimage.sh && bash framework/tools/wake/test-wake-install.sh"
+    "test:framework-shell": "bash framework/tools/quality/scripts/check-test-enumeration.sh && bash framework/tools/quality/scripts/test-check-test-enumeration.sh && python3 src/lease-broker/daemon_deadline_unittest.py && python3 src/lease-broker/normative_fragments_unittest.py && python3 src/lease-broker/receipt_challenge_unittest.py && python3 src/lease-broker/context_recovery_unittest.py && python3 src/lease-broker/recovery_runtime_unittest.py && python3 src/lease-broker/recovery_b1_adversarial_unittest.py && python3 src/lease-broker/framework_skill_portability_unittest.py && python3 src/mutator-gate/runtime_tools_unittest.py && python3 src/mutator-gate/runtime_launch_guard_unittest.py && python3 src/mutator-gate/version_coupling_unittest.py && python3 framework/tools/lease-broker/check-runtime-launches.py --root ../.. && bash framework/tools/codex/test-pr-diff-context.sh && bash framework/tools/qa/test-deps-preflight.sh && bash framework/tools/git/test-pr-review-gitea-comment.sh && bash framework/tools/git/test-pr-review-repo-host-override.sh && bash framework/tools/git/test-ci-queue-wait-branch-absent.sh && bash framework/tools/git/test-ci-queue-wait-tristate.sh && bash framework/tools/git/test-ci-queue-wait-github-checks.sh && bash framework/tools/git/test-pr-merge-queue-branch.sh && bash framework/tools/git/test-pr-merge-head-pin.sh && bash framework/tools/git/test-git-credential-mosaic.sh && bash framework/tools/git/test-gitea-token-identity.sh && bash framework/tools/woodpecker/test-terminal-green-contract.sh && bash framework/tools/_scripts/test-install-ordering-guard.sh && bash framework/tools/_scripts/test-mosaic-init-rce.sh && bash framework/tools/tmux/agent-send.test.sh && bash framework/tools/wake/test-wake-store-ack.sh && bash framework/tools/wake/test-wake-store-enqueue-race.sh && bash framework/tools/wake/test-wake-digest-hmac.sh && bash framework/tools/wake/test-wake-digest-quarantine.sh && bash framework/tools/wake/test-wake-detector.sh && bash framework/tools/wake/test-wake-fn-oracle.sh && bash framework/tools/wake/test-wake-reconcile.sh && bash framework/tools/wake/test-wake-beacon.sh && bash framework/tools/wake/test-wake-preimage.sh && bash framework/tools/wake/test-wake-install.sh"
   },
   "dependencies": {
     "@mosaicstack/brain": "workspace:*",