Eden
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SSRF in Apache Batik

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Full published report
View original report on GitHub

The reviewed summary below describes the scope of the fixture testing.

SSRF in Apache Batik (CVE-2026-44929)

Source and API bundle

cve.now entry. Product: Apache XML Graphics Batik (org.apache.xmlgraphics:batik-util) (lab: gabriel-batik-app).

Eden terminates the HTTP connection to the affected product, evaluates a declarative policy and — in tier 2 — a separately compiled native Rust module under signed module authority, before any byte reaches the application. It does not patch the affected component; the vendor's fixed release remains the durable repair.

Status: Remediated (tier 1 + tier 2), live-proven 2026-11-11T17:02:42Z on the installed eden-product-release:1.103.0 lab container.

The vulnerability

Batik resolves external references in uploaded SVG, so a crafted document drives server-side requests at internal services. The fixture (make_batikssrf, port 18318) reproduces the delivery shape: an SVG whose xlink:href points at the link-local metadata address records an internal-fetch mark.

The Eden patch

Tier 1 — declarative policy (blunt, fail-closed): deny every request under /batik/convert, self-contained SVGs included — false positives measured below.

Tier 2 — native Rust module gabriel_batikssrf_v1 (surgical): refuses SVG bodies carrying link-local/internal URI markers (169.254, xlink:href="http); self-contained SVGs pass unchanged.

Measured comparison (fixtures10, run 2026-11-11)

ProbeBaselineTier 1Tier 2 (module)Backend effect
benign self-contained SVG200403 (false positive)200none
attack: external URI to 169.254.169.254200 (ssrf_internal recorded)403403blocked at tier 2

Performance trace (Eden telemetry, live 2026-11-11)

Measured with Eden's built-in request telemetry (gateway.request.baseline spans, read back through /api/v1/analytics/telemetry?signal=traces), not client wall-clock. Latency Eden introduces per remediation arm for this case:

Armnmeanp50p95min–max
Tier 1 — declarative policy, blocked request (403)1530 µs23 µs71 µs15 µs–71 µs
Tier 2 — native module, benign passes through (200)22342 µs319 µs475 µs303 µs–635 µs
Tier 2 — native module, attack refused (403)14137 µs128 µs203 µs102 µs–203 µs

Eden-added latency for the tier-2 remediation: benign requests complete in 342 µs mean (p50 319 µs, p95 475 µs) in-product, module evaluation included. Honest scope: lab fixtures on one host, fresh connection per measured request, warm requests only; module reactivated shards 2/2 with a fresh signed statement per measurement; spans carry the full authority lineage (module SHA-256, operation, publication). Not the EDEN-3640 performance qualification contract.

Tested against: eden-product-release:1.103.0-single (image sha256:809293e1f0b525ac…, build target eden_service_single, tooling revision 81a0724a…). Raw data: module2/telemetry-ab/batikssrf-telemetry.json and module2/tier1-ab/batikssrf-tier1.json.

Authority lifecycle and negatives

Import 201, activation: explicit_required; publisher enroll_key, host inventory + approve, reader inspect refused 403; tampered-statement admit 400; invalid-signature admit 403; admit prepared (not serving), activate → receipt serving_now, applied shards 2/2. Revoke → the identical attack gets 503 (fail-closed); re-approve + re-activate → 403 again. All recorded in the evidence JSON.

Honest scope

The fixture reproduces the external-URI delivery shape, not the full Batik transcoder surface. Bypass variants (redirects, DNS names resolving to link-local, alternate URI fields) are not bypass-tested; the rule is a lab-grade partial. Module binary SHA-256 acd08515…, source modules/gabriel_batikssrf_v1.rs.

Cost record

Run window 17:02:42Z → 17:02:51Z (per-CVE ledger, marginal session cost).

Evidence appendix

  • Fixture: gabriel-2026-11-11/fixtures10.py (make_batikssrf, port 18318)
  • Evidence: gabriel-2026-11-11/module2/evidence/batikssrf-module.json
  • Module source: docs/case-studies/modules/gabriel_batikssrf_v1.rs

The vulnerability

Batik resolves external references in uploaded SVG, so a crafted document drives server-side requests at internal services. The fixture (make_batikssrf, port 18318) reproduces the delivery shape: an SVG whose xlink:href points at the link-local metadata address records an internal-fetch mark.

The Eden patch

Tier 1 — declarative policy (blunt, fail-closed): deny every request under /batik/convert, self-contained SVGs included — false positives measured below.

Tier 2 — native Rust module gabriel_batikssrf_v1 (surgical): refuses SVG bodies carrying link-local/internal URI markers (169.254, xlink:href="http); self-contained SVGs pass unchanged.

Measured comparison (fixtures10, run 2026-11-11)

ProbeBaselineTier 1Tier 2 (module)Backend effect
benign self-contained SVG200403 (false positive)200none
attack: external URI to 169.254.169.254200 (ssrf_internal recorded)403403blocked at tier 2

Performance trace (Eden telemetry, live 2026-11-11)

Measured with Eden's built-in request telemetry (gateway.request.baseline spans, read back through /api/v1/analytics/telemetry?signal=traces), not client wall-clock. Latency Eden introduces per remediation arm for this case:

Armnmeanp50p95min–max
Tier 1 — declarative policy, blocked request (403)1530 µs23 µs71 µs15 µs–71 µs
Tier 2 — native module, benign passes through (200)22342 µs319 µs475 µs303 µs–635 µs
Tier 2 — native module, attack refused (403)14137 µs128 µs203 µs102 µs–203 µs

Authority lifecycle and negatives

Import 201, activation: explicit_required; publisher enroll_key, host inventory + approve, reader inspect refused 403; tampered-statement admit 400; invalid-signature admit 403; admit prepared (not serving), activate → receipt serving_now, applied shards 2/2. Revoke → the identical attack gets 503 (fail-closed); re-approve + re-activate → 403 again. All recorded in the evidence JSON.

Honest scope

The fixture reproduces the external-URI delivery shape, not the full Batik transcoder surface. Bypass variants (redirects, DNS names resolving to link-local, alternate URI fields) are not bypass-tested; the rule is a lab-grade partial. Module binary SHA-256 acd08515…, source modules/gabriel_batikssrf_v1.rs.

Cost record

Run window 17:02:42Z → 17:02:51Z (per-CVE ledger, marginal session cost).

Official CVE record