fix(security): remediate Snyk Code Python findings (command injection, open redirect, raw JSON)

[devin-ai-integration]

SUMMARY

Root-cause fixes for Snyk Code (SAST) findings in the Python codebase:

• python/CommandInjection — scripts/cypress_run.py: the Cypress command was built as an f-string (spec path, browser from env, group id) and run via subprocess.Popen(cmd, shell=True). It is now an argv list passed without a shell (xvfb-run and its --server-args are split explicitly); the dry-run/RUN log output uses shlex.join.
• python/OpenRedirect — superset/views/core.py (explore redirect to datasource.default_endpoint) and superset/views/users/api.py (/api/v1/me/avatar redirect to Slack avatar URL). Added is_safe_redirect_target() in superset/utils/urls.py which allows only relative paths or absolute http(s) URLs, and rejects protocol-relative (//, \\) and non-web schemes (javascript:, data: …). Both redirect sites now gate on it.
• python/XSS — superset/views/api.py /api/v1/query/ returned a raw json.dumps string, which Flask serves as text/html. Wrapped in json_success() so it is returned as application/json.

Deliberately skipped (with rationale):

• python/OpenRedirect in superset/views/redirect.py:73 — already validated by is_safe_redirect_url() + DANGEROUS_SCHEMES block; finding is a false positive.
• python/XSS in superset/security/api.py, superset/async_events/api.py, superset/views/core.py (generate_json/json_error_response), superset/views/auth.py, superset/views/datasource/views.py — these already respond via self.response()/json_error_response()/json_success() (JSON application/json) or Jinja render_app_template, which autoescapes; no HTML reflection exists.
• python/PT (path traversal) in superset/app.py:119,126 — send_static_file delegates to Flask's send_from_directory, which already normalizes and confines to the static folder (raises NotFound otherwise); the override only changes the 404→204 for hot-update files.
• python/Jinja2AutoEscape in scripts/erd/erd.py, RELEASING/generate_email.py, superset/cli/… — these render non-HTML text templates (DOT/Markdown/plain-text email) from repo-controlled inputs; enabling HTML autoescape would corrupt output.
• python/HardcodedPassword/HardcodedSecret — all reported locations are test fixtures, example configs (superset/config.py placeholder defaults) or docs; no real secrets.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

N/A

TESTING INSTRUCTIONS

• ruff check / ruff format --check on changed files: pass.
• python scripts/cypress_run.py --parallelism-id 0 --dry-run prints the expected argv-based command.
• New parametrized unit test test_is_safe_redirect_target in tests/unit_tests/utils/urls_tests.py; run pytest tests/unit_tests/utils/urls_tests.py.
• curl -X POST /api/v1/query/ should now return Content-Type: application/json.

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
• Introduces new feature or API
• Removes existing feature or API

Link to Devin session: https://app.devin.ai/sessions/6722f19ed59a48bda02a0275375426c9
Open in Devin Desktop: https://app.devin.ai/desktop/session/6722f19ed59a48bda02a0275375426c9?variant=devin
Requested by: @shayanshafii

[devin-ai-integration]

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