Libreqos Security Audit

LibreQoS Security Audit

Use this skill for recurring LibreQoS security audit passes in this repo. It covers the Rust dependency baseline, network control-plane exposure review, bridged-interface/eBPF malformed-traffic review, and panic/error-handling/type loss review, node_manager privacy/auth/XSS review, and final executive-summary wrap-up. Use additional focused checks for Python, packaging, live-host configuration, secrets, and authentication flows outside these scopes.

Scope

• Keep the audit repo-local. Do not install or update global skills.
• Start from the current repo checkout and respect dirty worktree boundaries.
• Write results into the requested audit file. If no file is named, ask before creating one.
• Distinguish security findings from maintenance warnings. "Not maintained" is not a security issue by itself.
• Distinguish reachable vulnerabilities from unused-feature or irrelevant-feature advisories. A vulnerability in a feature LibreQoS does not use is not a security finding by itself.
• Treat an open listener as evidence, not a vulnerability by itself. Record a security finding only when the listener exposes exploitability, credential or session leakage, unauthenticated access beyond the intended demo/public mode, authorization bypass, brute-force exposure, remotely triggerable panic/DoS, or a control action reachable without the expected protection.

Step 1: Rust Dependency Audit

Run from src/rust/ unless the user asks for a narrower crate:

cargo audit
cargo machete
cargo tree --locked --workspace --depth 1

Use the depth-1 tree only for a quick workspace dependency summary. For every advisory or suspicious dependency, run an inverse tree query for the exact crate and version when Cargo can resolve it, such as cargo tree -i rand --locked or cargo tree -i rand@0.8.5 --locked. If Cargo cannot resolve the package ID, use cargo audit's dependency tree plus rg searches through manifests and source files.

If sandboxing blocks Cargo registry or advisory-db access, rerun the blocked command with approval instead of switching to stale data.

Reachability Rubric

Treat an advisory as a security finding when at least one of these is true:

• LibreQoS directly imports the vulnerable crate and calls the affected API.
• A current workspace crate exposes the vulnerable behavior through a LibreQoS runtime surface: lqosd node-manager HTTP/websocket handlers, lqos_bus message handling, lqos_config parsing for network.json / ShapedDevices.csv / config files, lqos_network_devices runtime access to shaped-device and topology state, lqos_topology / lqos_topology_compile topology projection, lqos_probe active probing, lqos_overrides, uisp_integration, lqos_python, lqos_setup, lqos_netplan_helper, lqos_sys TC/XDP/eBPF interaction, queue/bakery crates, or support-tool archive/input handling.
• The advisory applies to default features or enabled features in Cargo.toml / Cargo.lock, and no code-level usage check is needed for the vulnerable behavior to be present.

Expected evidence searches include the affected crate name in Cargo.toml files, affected function/type names in src/rust/**, relevant feature names in manifests and Cargo.lock, and logger/auth/network/file-parsing entry points when the advisory depends on runtime conditions.

Treat an advisory as not currently security-relevant when all of these are true:

• The affected crate is present only through an unused optional feature, build-only path, test-only path, or API surface LibreQoS does not call.
• Feature flags and source search support that conclusion.
• The audit note records what was checked.

If the evidence is incomplete, record it as "reachability unknown" and list the specific follow-up needed. Do not call it safe.

Triage Rules

For every cargo audit result:

• Record CVE/RUSTSEC/GHSA security advisories as findings only when they meet the reachability rubric above.
• For each security finding, include:
  • the advisory ID
  • the repo-relative path to the Cargo.toml that imports the vulnerable crate
  • repo-relative source paths that call the affected API or make the dependency reachable, when applicable
  • a short vulnerability description
  • recommended actions
• Do not list maintenance-only advisories as security findings. Put them in a separate non-security notes section.
• If an advisory depends on specific feature flags, runtime configuration, or API calls, verify those paths with rg before writing the conclusion.
• If reachability is unclear, use "reachability unknown" and say exactly what was checked and what remains unknown.

For cargo machete results:

• Record unused dependencies separately from security findings.
• Include the repo-relative manifest path and dependency name.
• Recommend removal plus the smallest focused validation command. Use a real crate name in the audit note, for example cargo check -p lqos_network_devices.

For cargo tree:

• Use depth-1 output only for a quick workspace summary.
• Use inverse tree queries to identify direct and transitive import paths for findings.
• Keep dependency-surface summaries short and tied to an audit decision.

Audit Section Checklist

The audit-file section must include:

• Heading: Rust dependency audit.
• Date, scope, and exact commands run.
• Summary bullets covering dependency count, security findings, unused dependencies, and non-security warnings.
• One subsection per security finding with advisory ID, affected crate, import paths, source-use paths where applicable, short description, reachability decision, and recommended actions.
• A separate unused-dependencies subsection for cargo machete output.
• A separate non-security warnings subsection for unmaintained or informational advisories.
• No placeholders, no ..., and no unresolved <angle-bracket> tokens.

Step 2: Network Control-Plane Exposure Audit

Use this step when the audit turns to external threats over the LibreQoS control plane.

Scope Assumptions

• Assume the operator installed the Caddy / SSL / TLS option.
• Treat Linux, Ubuntu, kernel, and distribution package vulnerabilities as out of scope because LibreQoS cannot fix them in-repo.
• Treat the control interface as in scope. Anything listening or reachable on the control interface should be reviewed.
• Treat the two bridge interfaces, whether XDP or Linux bridge backed by eBPF, as out of scope for this section.
• Include the sibling ../../lqos_api/ repo as read-only audit context when it is present, because the API is exposed behind Caddy.
• Do not edit ../../lqos_api/ unless the user explicitly authorizes cross-repo changes.

Evidence To Gather

Review these surfaces first:

src/rust/lqos_setup/src/ssl.rs
src/rust/lqos_setup/src/web.rs
src/rust/lqosd/src/node_manager/
docs/v2.0/https-caddy.md
docs/v2.0/api.md
../../lqos_api/src/
../../lqos_api/README.md

Use rg searches for listener addresses, routes, middleware, auth checks, cookie settings, CORS, Caddy upstreams, and panic-prone request handling:

rg "bind\\(|TcpListener|listen|reverse_proxy|Caddy|CorsLayer|very_permissive|allow_anonymous|SameSite|Cookie|x-bearer|route_layer|unwrap\\(" src/rust docs ../../lqos_api

For each reachable service or route, identify:

• listener address and port
• whether Caddy proxies it and whether the direct port remains reachable
• authentication and authorization mechanism
• unauthenticated routes and whether they expose control, data, or only health/docs
• state-changing routes and their protection
• cookie flags, CORS policy, CSRF/origin checks, and session behavior
• rate limits or backoff for login/API authentication attempts
• request paths where malformed unauthenticated input can panic

Triage Rules

Count these as likely security findings when evidence supports them:

• a direct control-plane HTTP listener bypasses the expected Caddy/TLS path for authenticated API traffic
• a route that changes state or exposes sensitive operational data is reachable without the expected auth, except for the explicit public/demo read-only mode
• an auth or request middleware can panic on unauthenticated remote input
• credentialed CORS, cookie flags, or missing CSRF/origin checks let another browser origin use an operator session
• login or bearer-token checks lack reasonable throttling for a network-exposed control-plane service

Do not count these as findings by themselves:

• Caddy or LibreQoS listening on a port when the route is protected as intended
• Caddy serving HTTPS for the WebUI/API path
• public API documentation that exposes only endpoint shape and no secret or state-changing capability
• allow_anonymous when the operator intentionally enabled the documented public/demo read-only mode
• first-run setup exposure when the setup token and lifecycle are being audited separately, unless the current section finds a concrete bypass

Audit Section Checklist

The audit-file section must include:

• Heading: Network control-plane audit.
• Date, scope assumptions, and exact files or directories reviewed.
• Summary bullets separating findings from observations.
• One subsection per finding with the repo-relative path, short description, exposure/threat, and recommended actions.
• A separate observations / not-findings subsection for open listeners or public docs that are intentional and not vulnerable by themselves.
• No placeholders, no ..., and no unresolved <angle-bracket> tokens.

Step 3: Bridged Interface / eBPF Malformed-Traffic Audit

Use this step when the audit turns to bridged interfaces and the eBPF datapath. This step is about malformed-packet handling, DoS, map exhaustion, ring-buffer backpressure, packet-rate debug logging, and userspace handling of eBPF events. It is not about the control interface.

Review these BPF-specific surfaces first:

src/rust/lqos_sys/src/bpf/lqos_kern.c
src/rust/lqos_sys/src/bpf/common/debug.h
src/rust/lqos_sys/src/bpf/common/dissector.h
src/rust/lqos_sys/src/bpf/common/dissector_tc.h
src/rust/lqos_sys/src/bpf/common/flows.h
src/rust/lqos_sys/src/bpf/common/heimdall.h
src/rust/lqos_sys/src/bpf/common/lpm.h
src/rust/lqos_sys/src/bpf/common/throughput.h
src/rust/lqos_sys/src/bpf/common/maximums.h
src/rust/lqos_sys/src/lqos_kernel.rs
src/rust/lqosd/src/throughput_tracker/
src/rust/lqos_heimdall/src/

Use this search as the starting point:

rg "bpf_debug\\(|frag_off|ihl|tot_len|doff|BPF_MAP_TYPE_HASH|BPF_MAP_TYPE_PERCPU_HASH|BPF_MAP_TYPE_LRU|MAX_FLOWS|MAX_TRACKED_IPS|bpf_ringbuf_output|bpf_probe_read_kernel|data_end|SKB_OVERFLOW|metadata|queue_mapping" src/rust/lqos_sys/src src/rust/lqosd/src/throughput_tracker src/rust/lqos_heimdall/src

For each packet path, identify the concrete behavior for:

• malformed Ethernet, VLAN, PPPoE, MPLS, IPv4, IPv6, TCP, UDP, and ICMP input
• IPv4 ihl, total length, and fragmentation checks before L4 parsing
• IPv6 extension headers and fragments
• bounded-loop limits for stacked headers and TCP options
• unshaped or spoofed traffic creating pinned-map entries
• map type, max entries, LRU behavior, and insert-failure behavior
• bpf_trace_printk / bpf_debug calls reachable from bridged traffic
• ring-buffer size checks, backpressure, drop counters, and userspace panics
• metadata paths where malformed packets can become unexpected drops

Count a finding when malformed, spoofed, or high-cardinality traffic can cause packet-rate expensive work, non-LRU map exhaustion, bogus flow/RTT/retransmit state, unexpected packet drops, userspace panic, or unreported loss of capture events. Do not count verifier-enforced memory safety, unknown non-IP traffic that merely fails open, or untested live reachability claims as findings by themselves.

Step 4: Panic, Error-Handling, and Type-Loss Audit

Use this step when the audit turns to code paths that can panic, hide errors, or silently lose data. Include the sibling ../../lqos_api/src/ when it is present because it is part of the deployed control-plane surface, but do not edit that repo unless the user explicitly authorizes cross-repo changes.

Start with these searches, then inspect only runtime-reachable code. Exclude tests, fixtures, generated output, vendored bindings, and historical copies such as LibreQoS-old.py unless the user explicitly puts them in scope.

rg -n "\\bpanic!\\(|\\.unwrap\\(|\\.expect\\(|unreachable!\\(|todo!\\(|unimplemented!\\(|assert!\\(|from_raw_parts|transmute|unsafe \\{|as (u8|u16|u32|usize|i8|i16|i32|f32)|unwrap_or_default\\(|except Exception|except:|pass$" src/rust src --glob '*.py' ../../lqos_api/src
rg -n "as u32|as u16|as f32|partial_cmp\\(.*\\)\\.unwrap|to_str\\(\\)\\.unwrap|parse\\(\\)\\.unwrap|try_into\\(\\)\\.unwrap" src/rust ../../lqos_api/src
rg -n "except Exception|except:|pass$|sys.exit|int\\(|float\\(" src --glob '*.py' --glob '!LibreQoS-old.py' --glob '!LibreQoS-ancient.py' --glob '!LibreQoS.py.new'

For each candidate, identify:

• file name and exact line number
• whether the code is request-time, packet-time, config/import-time, startup-only, test-only, or generated/vendor code
• whether an external user, bridged-interface packet, operator-managed file, or internal telemetry value can trigger the path
• whether the impact is panic/DoS, poisoned shared state, incorrect rejection, silent fallback, lossy conversion, wrapped counters, non-finite float handling, or misleading operational data

Count a finding when evidence supports one of these:

• a request, websocket message, packet event, or operator-managed file can panic a runtime task instead of returning an error
• malformed input can poison or permanently break shared runtime state
• error handling silently continues with a different shaping, auth, or telemetry result that an operator would not see
• numeric conversion narrows kernel counters, flow counters, bandwidth values, or timestamps in a way that can wrap, saturate unexpectedly, become non-finite, or otherwise lose operational data
• an unsafe block reads caller-provided memory without a size check or serializes uninitialized padding bytes

Do not count these as findings by themselves:

• unwrap / expect in tests, examples, benchmarks, one-shot setup validation, or process startup where failure stops boot cleanly
• unsafe FFI wrappers that validate sizes and keep pointer lifetimes local
• protocol fields that are intentionally narrower when the code checks range or logs/clamps loss before export
• broad Python exception handling that only preserves backwards-compatible tolerance and does not change shaping/auth/security behavior

The audit-file section must include:

• Heading: Panic, error-handling, and type-loss audit.
• Date, scope, and exact searches or files reviewed.
• Summary bullets separating confirmed findings, reachability-unknown items, and observations/not-findings.
• One subsection per finding with the repo-relative path:line, short description, exposure/threat, and recommended actions.
• No placeholders, no ..., and no unresolved <angle-bracket> tokens.

Step 5: Node Manager Privacy, Auth, and XSS Audit

Use this step when reviewing node_manager for missing anonymization of PII, missing authentication or authorization on data access, browser-storage exposure, and XSS. Review source files, not generated bundles, unless a generated artifact is the only shipped source for that behavior.

Start with these surfaces:

src/rust/lqosd/src/node_manager/run.rs
src/rust/lqosd/src/node_manager/static_pages.rs
src/rust/lqosd/src/node_manager/auth.rs
src/rust/lqosd/src/node_manager/ws.rs
src/rust/lqosd/src/node_manager/ws/messages.rs
src/rust/lqosd/src/node_manager/local_api/
src/rust/lqosd/src/node_manager/js_build/src/
src/rust/lqosd/src/node_manager/static2/template.html
docs/v2.0/node-manager-ui.md
docs/v2.0/components.md

Use these searches as a starting point:

rg -n "localStorage|sessionStorage|document\\.cookie|innerHTML|outerHTML|insertAdjacentHTML|eval\\(|Function\\(|onclick=|onerror=|sanitize|DOMPurify|redact|redaction|redactable|allow_anonymous|auth_layer|route_layer|LoginResult|ReadOnly|Admin|Denied" src/rust/lqosd/src/node_manager docs/v2.0
rg -n "innerHTML\\s*=.*(\\+|`)|simpleRowHtml\\(|href=.*\\+|data-[^=]+=|textContent|innerText" src/rust/lqosd/src/node_manager/js_build/src --glob '*.js'
rg -n "ShapedDevice|network_json|CircuitById|AllShapedDevices|NetworkJson|Search|UnknownIps|CircuitDirectory|device_name|circuit_name|mac|ipv4|ipv6|comment" src/rust/lqosd/src/node_manager

For each candidate, identify:

• the exact path:line
• whether access is unauthenticated, anonymous read-only, authenticated read-only, or admin-only
• whether the exposed data includes subscriber/customer identifiers, circuit names/IDs, device names/IDs, IPs, MACs, comments, topology names, tickets, or integration secrets
• whether redaction happens server-side, in the transport payload, or only in the browser display
• whether browser storage persists credentials, session tokens, topology drafts, dashboard layouts, interface names, VLANs, or other operational data
• whether untrusted strings are inserted with innerHTML, HTML tooltips, attributes, inline handlers, or URLs without escaping and protocol validation

Count a finding when evidence supports one of these:

• anonymous/demo/read-only access can retrieve raw PII or sensitive operational data with no server-side anonymization
• a route, websocket request, local API, static fallback, or file-serving path exposes data without the expected auth boundary
• state-changing websocket/local API behavior is available to read-only or anonymous users without a documented reason
• operator/customer/integration-controlled strings can reach innerHTML or HTML attributes without escaping
• an XSS would expose a session token, API key, config secret, localStorage value, or pending control-plane operation
• localStorage retains sensitive topology/configuration data beyond the browser session or logout without a clear need

Do not count these as findings by themselves:

• static JS/CSS/images served without auth when they contain no operator data, credentials, or secrets
• client-side redaction that is documented as screenshot/demo display redaction, unless the same mode is used as the privacy boundary for anonymous/public access
• admin-only config views that already redact integration secrets before sending them to the browser
• innerHTML used only for fixed icons, fixed Bootstrap markup, or escaped values

The audit-file section must include:

• Heading: Node Manager privacy, auth, and XSS audit.
• Date, scope, exact searches or files reviewed, and any excluded generated/vendor output.
• Summary bullets separating confirmed findings, hardening observations, and not-findings.
• One subsection per finding with repo-relative path:line, short description, exposure/threat, and recommended actions.
• A short localStorage/sessionStorage/cookie note, even when no sensitive localStorage token is found.
• No placeholders, no ..., and no unresolved <angle-bracket> tokens.

Step 6: Audit Introduction, Executive Summary, Conclusion, and Grade

Use this step after the requested audit sections have enough findings to summarize. Keep the write-up brief enough for release planning while preserving the concrete evidence in the detailed sections below.

At the beginning of the audit file, add:

• Introduction: the audit date, overall scope, what was static-only, and major exclusions such as Linux/Ubuntu vulnerabilities, live firewall state, or deployment-specific controls not visible in the checkout.
• Executive summary: bullet points that signal the actionable issues found later in the document. Include the highest-risk findings, non-findings that matter to release confidence, and the recommended fix priority.
• An overall letter grade from A to F. Use the grade as a concise release posture signal, not as a substitute for findings.

At the end of the audit file, add:

• Conclusion: restate the overall grade and explain the security posture in a balanced way.
• Call out what LibreQoS is doing right, such as dependency health, auth layers, TLS/Caddy direction, redaction of secrets, verifier-conscious eBPF bounds checks, or any other strengths actually found in the detailed sections.
• Call out what needs work, prioritizing concrete risk over volume of findings.
• Keep recommendations aligned with the detailed findings. Do not introduce new unsupported claims in the conclusion.

Suggested grading rubric:

• A: No confirmed high-impact release issues, strong auth/session boundaries, validated input handling, and only minor hardening items remain.
• B: Good foundations with a few bounded, actionable hardening issues.
• C: Acceptable foundations, but multiple actionable issues remain in control-plane, WebUI, privacy, panic/DoS, or observability paths.
• D: Security-critical issues are likely reachable or broad auth/privacy boundaries are missing.
• F: Known unauthenticated compromise, widespread secret exposure, or a release-blocking vulnerability with no mitigation.

The introduction, executive summary, and conclusion must not contain placeholders, speculative certainty, or findings that are absent from the body of the audit.

Validation

• Re-read the audit section before returning; remove placeholders and vague conclusions.
• After changing any repo file, run the repo's anti-slop review path and fix non-zero slop before finishing.