Charon/docs/reports/qa_report.md

QA Audit Report — PR-1: Allow Empty Value in UpdateSetting

Date: 2026-03-17 Scope: Remove binding:"required" from Value field in UpdateSettingRequest File: backend/internal/api/handlers/settings_handler.go

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QA Security Audit Report — Rate Limit CI Fix

Audited by: QA Security Auditor Date: 2026-03-17 Spec reference: docs/plans/rate_limit_ci_fix_spec.md Files audited:

• scripts/rate_limit_integration.sh
• Dockerfile (GeoIP section, non-CI path)
• .github/workflows/rate-limit-integration.yml

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Pre-Commit Check Results

Check	Command	Result
Bash syntax	bash -n scripts/rate_limit_integration.sh	✅ PASS (exit 0)
Pre-commit hooks	lefthook run pre-commit (project uses lefthook; no .pre-commit-config.yaml)	✅ PASS — all 6 hooks passed: check-yaml, actionlint, end-of-file-fixer, trailing-whitespace, dockerfile-check, shellcheck
Caddy admin API trailing slash (workflow)	grep -n "2119" .github/workflows/rate-limit-integration.yml	✅ PASS — line 71 references /config/ (trailing slash present)
Caddy admin API trailing slash (script)	All 6 occurrences of localhost:2119/config in script	✅ PASS — all use /config/

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Security Focus Area Results

1. Credential Handling — TMP_COOKIE

mktemp usage: TMP_COOKIE=$(mktemp) at line 208. Creates a file in /tmp with 600 permissions via the OS. ✅ SECURE.

Removal on exit: The cleanup() function at line 103 removes the file with rm -f "${TMP_COOKIE:-}". However, cleanup is only registered via explicit calls — there is no trap cleanup EXIT. Only trap on_failure ERR is registered (line 108).

Gap: On 5 early exit 1 paths after line 208 (login failure L220, auth failure L251, Caddy readiness failure L282, security config failure L299, and handler verification failure L316), cleanup is never called. The cookie file is left in /tmp.

Severity: LOW — The cookie contains session credentials for a localhost test server (ratelimit@example.local / password123, non-production). CI runners are ephemeral and auto-cleaned. Local runs will leave a /tmp/tmp.XXXXXX file until next reboot or manual cleanup.

Note: The exit at line 386 (inside the 429 enforcement failure block) intentionally skips cleanup to leave containers running for manual inspection. This is by design and acceptable.

Recommendation: Add trap cleanup EXIT immediately after trap on_failure ERR (line 109) to ensure the cookie file is always removed.

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2. curl — Sensitive Values in Command-Line Arguments

Cookie file path is passed via -c ${TMP_COOKIE} and -b ${TMP_COOKIE} (unquoted). No credentials, tokens, or API keys are passed as command-line arguments. All authentication is via the cookie file (read/write by path), which is the correct pattern — cookie values never appear in ps output.

Finding (LOW): ${TMP_COOKIE} is unquoted in all 6 curl invocations. mktemp on Linux produces paths of the form /tmp/tmp.XXXXXX which never contain spaces or shell metacharacters under default $TMPDIR. However, under a non-standard $TMPDIR (e.g., /tmp/my dir/) this would break. This is a portability issue, not a security issue.

Recommendation: Quote "${TMP_COOKIE}" in all curl invocations.

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3. Shell Injection

All interpolated values in curl -d payloads are either:

• Script-level constants (RATE_LIMIT_REQUESTS=3, RATE_LIMIT_WINDOW_SEC=10, RATE_LIMIT_BURST=1, TEST_DOMAIN=ratelimit.local, BACKEND_CONTAINER=ratelimit-backend)
• Values derived from API responses stored in double-quoted variables ("$CREATE_RESP", "$SEC_CONFIG_RESP")

No shell injection vector exists. All heredoc expansions (cat <<EOF...EOF) expand only the hardcoded constants listed above.

The UUID extraction pattern at line 429 includes ${TEST_DOMAIN} unquoted within a grep -o pattern, but because the variable expands to ratelimit.local (controlled constant), this has no injection risk. The . in ratelimit.local is treated as a regex wildcard but in this context only matches the intended hostname. ✅ PASS.

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4. set -euo pipefail Compatibility

The new status-capture idiom:

LOGIN_STATUS=$(curl -s -w "\n%{http_code}" ... | tail -n1)

Behavior under set -euo pipefail:

• Network failure (curl exits non-zero, e.g., ECONNREFUSED): pipefail propagates curl's non-zero exit through the pipeline; the assignment fails; set -e fires the on_failure ERR trap and exits. ✅ Correct.
• HTTP error (curl exits 0, HTTP 4xx/5xx): curl outputs \n{code}; tail -n1 extracts the code; assignment succeeds; subsequent [ "$LOGIN_STATUS" != "200" ] detects the failure. ✅ Correct.
• Empty body edge case: If curl returns an empty body, output is \n200. tail -n1 → 200; head -n-1 → empty string. Status check still works. ✅ Correct.

The SEC_CONFIG_RESP split pattern (tail -n1 for status, head -n-1 for body) is correct for both single-line and multiline JSON responses. ✅ PASS.

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5. Workflow Secrets Exposure

The workflow (rate-limit-integration.yml) contains no ${{ secrets.* }} references. All test credentials are hardcoded constants in the script (ratelimit@example.local / password123), appropriate for an ephemeral test user that is registered and used only within the test run.

$GITHUB_STEP_SUMMARY output includes: container status, API config JSON, container logs. None of these contain secrets or credentials. The security config JSON may contain rate limit settings (integers) but nothing sensitive.

No accidental log exposure identified. ✅ PASS.

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6. GeoIP Change — Supply-Chain Risk

Change: The non-CI Dockerfile build path previously ran sha256sum -c - against GEOLITE2_COUNTRY_SHA256. This was removed. The remaining guard is [ -s /app/data/geoip/GeoLite2-Country.mmdb ] (file-size non-empty check).

Risk assessment (MEDIUM): The download source is https://github.com/P3TERX/GeoLite.mmdb/raw/download/GeoLite2-Country.mmdb, a public GitHub repository. If this repository is compromised or the file is replaced with a malicious binary:

• The -s check only verifies the file is non-empty
• The application loads it at CHARON_GEOIP_DB_PATH for IP geolocation — a non-privileged read operation
• A malicious file would not achieve RCE via MMDb parsing in the MaxMind reader library (no known attack surface), but could corrupt GeoIP lookups silently

This is an acknowledged, pre-existing architectural limitation documented in the spec. The sha256sum check was ineffective by design because the P3TERX repository updates the file continuously while the pinned hash only updates weekly via update-geolite2.yml. The new behavior (accept any non-empty file) is more honest about the actual constraint.

Spec compliance: ARG GEOLITE2_COUNTRY_SHA256 is retained in the Dockerfile (line ~441) as required by the spec, preserving update-geolite2.yml workflow compatibility. ✅ PASS.

Residual risk: MEDIUM. Mitigated by: (1) wget uses HTTPS to fetch from GitHub (TLS in transit), (2) downstream Trivy scans of the built image would flag a malicious MMDB independently, (3) the GeoIP reader is sandboxed to a read operation with no known parse-exploit surface.

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Correctness Against Spec

Spec Change	Implemented	Verified
C1: Login status check (Step 4)	✅ Yes — LOGIN_STATUS checked, fails fast on non-200	Script lines 211–220
C2: Proxy host creation — auth failures fatal, 409 continues	✅ Yes — 401/403 abort, other non-201 continues	Script lines 248–256
C3: Caddy admin API readiness gate before security config POST	✅ Yes — 20-retry loop before SEC_CFG call	Script lines 274–284
C4: Security config POST status checked	✅ Yes — SEC_CONFIG_STATUS checked, body logged on error	Script lines 286–301
C5: verify_rate_limit_config failure is hard exit	✅ Yes — prints debug and exit 1	Script lines 307–318
C6: Pre-verification sleep increased 5 → 8 s	✅ Yes — sleep 8	Script line 305
C7: Trailing slash on /config/	✅ Yes — all 6 script occurrences; workflow line 71	Confirmed by grep
Dockerfile: sha256sum removed from non-CI path	✅ Yes — only -s check remains	Dockerfile lines ~453–463
Dockerfile: ARG GEOLITE2_COUNTRY_SHA256 retained	✅ Yes — line ~441	Dockerfile audited
Workflow: debug dump uses /config/	✅ Yes — line 71	Confirmed by grep

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Findings Summary

ID	Severity	Area	Description
M1	MEDIUM	Dockerfile supply-chain	GeoIP downloaded without hash; -s is minimum viability only. Accepted trade-off per spec — hash was perpetually stale.
L1	LOW	Shell security	${TMP_COOKIE} unquoted in 6 curl invocations. No practical impact under standard $TMPDIR.
L2	LOW	Temp file hygiene	No trap cleanup EXIT; TMP_COOKIE and containers not cleaned on 5 early failure paths (lines 220, 251, 282, 299, 316). Low sensitivity (localhost test credentials only).

No CRITICAL or HIGH severity findings.

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Overall Verdict

✅ APPROVED

All spec-required changes are correctly implemented. No OWASP Top 10 vulnerabilities were introduced. The two LOW findings (unquoted variable, missing EXIT trap) are hygiene improvements that do not block the fix. The MEDIUM GeoIP supply-chain concern is a pre-existing architectural trade-off explicitly acknowledged in the spec.

Recommended follow-up (non-blocking)

Add trap cleanup EXIT immediately after trap on_failure ERR in scripts/rate_limit_integration.sh to ensure TMP_COOKIE is always removed and containers are cleaned on all exit paths. Purpose: Allow admins to set a setting to an empty string value (required to fix the fresh-install CrowdSec enabling bug where value was legitimately empty).

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Overall Verdict: APPROVED

All structural, linting, and security gates pass. The change is correctly scoped to the build-only frontend-builder stage and introduces no new attack surface in the final runtime image.

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Changes Under Review

Element	Location	Description
ARG NPM_VERSION=11.11.1	Line 30 (global ARG block)	Pinned npm version with Renovate comment
ARG NPM_VERSION	Line 105 (frontend-builder)	Bare re-declaration to inherit global ARG into stage
# hadolint ignore=DL3017	Line 106	Lint suppression for intentional apk upgrade
RUN apk upgrade --no-cache && ...	Lines 107–109	Three-command RUN: OS patch + npm upgrade + cache clear
RUN npm ci	Line 111	Unchanged dependency install follows the new RUN block

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Gate Summary

#	Gate	Result	Details
1	Global ARG NPM_VERSION present with Renovate comment	PASS	Line 30; # renovate: datasource=npm depName=npm at line 29
2	ARG NPM_VERSION bare re-declaration inside stage	PASS	Line 105
3	# hadolint ignore=DL3017 on own line before RUN block	PASS	Line 106
4	RUN block — three correct commands	PASS	Lines 107–109: apk upgrade --no-cache, npm install -g npm@${NPM_VERSION} --no-fund --no-audit, npm cache clean --force
5	RUN npm ci still present and follows new block	PASS	Line 111
6	FROM line unchanged	PASS	node:24.14.0-alpine@sha256:7fddd9ddeae8196abf4a3ef2de34e11f7b1a722119f91f28ddf1e99dcafdf114
7	${NPM_VERSION} used (no hard-coded version)	PASS	Confirmed variable reference in install command
8	Trivy config scan (HIGH/CRITICAL)	PASS	0 misconfigurations
9	Hadolint (new code area)	PASS	No errors or warnings; only pre-existing info-level DL3059 at unrelated lines
10	Runtime image isolation	PASS	Only /app/frontend/dist artifacts copied into final image via line 535
11	--no-audit acceptability	PASS	Applies only to the single-package global npm upgrade; npm ci is unaffected
12	npm cache clean --force safety	PASS	Safe cache clear between npm tool upgrade and dependency install

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1. Dockerfile Structural Verification

Global ARG block (lines 25–40)

29: # renovate: datasource=npm depName=npm
30: ARG NPM_VERSION=11.11.1

Both the Renovate comment and the pinned ARG are present in the correct order. Renovate will track npm releases on datasource=npm and propose version bumps automatically.

frontend-builder stage (lines 93–115)

93:  FROM --platform=$BUILDPLATFORM node:24.14.0-alpine@sha256:... AS frontend-builder
...
105: ARG NPM_VERSION
106: # hadolint ignore=DL3017
107: RUN apk upgrade --no-cache && \
108:     npm install -g npm@${NPM_VERSION} --no-fund --no-audit && \
109:     npm cache clean --force
...
111: RUN npm ci

All structural requirements confirmed: bare re-declaration, lint suppression on dedicated line, three-command RUN, and unmodified npm ci.

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2. Security Tool Results

Trivy config scan

Command: docker run aquasec/trivy config Dockerfile --severity HIGH,CRITICAL

Report Summary
┌────────────┬────────────┬───────────────────┐
│   Target   │    Type    │ Misconfigurations │
├────────────┼────────────┼───────────────────┤
│ Dockerfile │ dockerfile │         0         │
└────────────┴────────────┴───────────────────┘

No HIGH or CRITICAL misconfigurations detected.

Hadolint

Command: docker run hadolint/hadolint < Dockerfile

Findings affecting the new code: none.

Pre-existing info-level findings (unrelated to this change):

Line	Rule	Message
78, 81, 137, 335, 338	DL3059 info	Multiple consecutive RUN — pre-existing pattern
492	SC2012 info	Use find instead of ls — unrelated

No errors or warnings in the frontend-builder section.

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3. Logical Security Review

Attack surface — build-only stage

The frontend-builder stage is strictly a build artifact producer. The final runtime image receives only compiled frontend assets via a single targeted COPY:

COPY --from=frontend-builder /app/frontend/dist /app/frontend/dist

The Alpine OS packages upgraded by apk upgrade --no-cache, the globally installed npm binary, and all node_modules are confined to the builder layer and never reach the runtime image. The CVE remediation has zero footprint in the deployed container.

--no-audit flag

--no-audit suppresses npm audit output during npm install -g npm@${NPM_VERSION}. This applies only to the single-package global npm tool upgrade, not to the project dependency installation. npm ci on line 111 installs project dependencies from package-lock.json and is unaffected by this flag. Suppressing audit during a build-time tool upgrade is the standard pattern for avoiding advisory database noise that cannot be acted on during the image build.

npm cache clean --force

Clears the npm package cache between the global npm upgrade and the npm ci run. This is safe: it ensures the freshly installed npm binary is used without stale cache entries left by the older npm version bundled in the base image. The --force flag suppresses npm's deprecation warning about manual cache cleaning; it does not alter the clean operation itself.

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Blocking Issues

None.