feat(alerting): SSRF guard on outbound connection URL

Rejects webhook URLs that resolve to loopback, link-local, or RFC-1918
private ranges (IPv4 + IPv6 ULA fc00::/7). Enforced on both create and
update in OutboundConnectionServiceImpl before persistence; returns 400
Bad Request with "private or loopback" in the body.

Bypass via `cameleer.server.outbound-http.allow-private-targets=true`
for dev environments where webhooks legitimately point at local
services. Production default is `false`.

Test profile sets the flag to `true` in application-test.yml so the
existing ITs that post webhooks to WireMock on https://localhost:PORT
keep working. A dedicated OutboundConnectionSsrfIT overrides the flag
back to false (via @TestPropertySource + @DirtiesContext) to exercise
the reject path end-to-end through the admin controller.

Plan 01 scope; required before SaaS exposure (spec §17).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
hsiegeln
2026-04-20 14:17:44 +02:00
parent f4c2cb120b
commit 5ebc729b82
6 changed files with 240 additions and 1 deletions

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@@ -7,6 +7,8 @@ import com.cameleer.server.core.outbound.OutboundConnectionService;
import org.springframework.http.HttpStatus; import org.springframework.http.HttpStatus;
import org.springframework.web.server.ResponseStatusException; import org.springframework.web.server.ResponseStatusException;
import java.net.URI;
import java.net.URISyntaxException;
import java.time.Instant; import java.time.Instant;
import java.util.List; import java.util.List;
import java.util.UUID; import java.util.UUID;
@@ -15,20 +17,24 @@ public class OutboundConnectionServiceImpl implements OutboundConnectionService
private final OutboundConnectionRepository repo; private final OutboundConnectionRepository repo;
private final AlertRuleRepository ruleRepo; private final AlertRuleRepository ruleRepo;
private final SsrfGuard ssrfGuard;
private final String tenantId; private final String tenantId;
public OutboundConnectionServiceImpl( public OutboundConnectionServiceImpl(
OutboundConnectionRepository repo, OutboundConnectionRepository repo,
AlertRuleRepository ruleRepo, AlertRuleRepository ruleRepo,
SsrfGuard ssrfGuard,
String tenantId) { String tenantId) {
this.repo = repo; this.repo = repo;
this.ruleRepo = ruleRepo; this.ruleRepo = ruleRepo;
this.ssrfGuard = ssrfGuard;
this.tenantId = tenantId; this.tenantId = tenantId;
} }
@Override @Override
public OutboundConnection create(OutboundConnection draft, String actingUserId) { public OutboundConnection create(OutboundConnection draft, String actingUserId) {
assertNameUnique(draft.name(), null); assertNameUnique(draft.name(), null);
validateUrl(draft.url());
OutboundConnection c = new OutboundConnection( OutboundConnection c = new OutboundConnection(
UUID.randomUUID(), tenantId, draft.name(), draft.description(), UUID.randomUUID(), tenantId, draft.name(), draft.description(),
draft.url(), draft.method(), draft.defaultHeaders(), draft.defaultBodyTmpl(), draft.url(), draft.method(), draft.defaultHeaders(), draft.defaultBodyTmpl(),
@@ -46,6 +52,7 @@ public class OutboundConnectionServiceImpl implements OutboundConnectionService
if (!existing.name().equals(draft.name())) { if (!existing.name().equals(draft.name())) {
assertNameUnique(draft.name(), id); assertNameUnique(draft.name(), id);
} }
validateUrl(draft.url());
// Narrowing allowed-envs guard: if the new draft restricts to a non-empty set of envs, // Narrowing allowed-envs guard: if the new draft restricts to a non-empty set of envs,
// find any envs that existed before but are absent in the draft. // find any envs that existed before but are absent in the draft.
@@ -107,4 +114,23 @@ public class OutboundConnectionServiceImpl implements OutboundConnectionService
} }
}); });
} }
/**
* Validate the webhook URL against SSRF pitfalls. Translates the guard's
* {@link IllegalArgumentException} into a 400 Bad Request with the guard's
* message preserved, so the client sees e.g. "private or loopback".
*/
private void validateUrl(String url) {
URI uri;
try {
uri = new URI(url);
} catch (URISyntaxException e) {
throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid URL: " + url);
}
try {
ssrfGuard.validate(uri);
} catch (IllegalArgumentException e) {
throw new ResponseStatusException(HttpStatus.BAD_REQUEST, e.getMessage(), e);
}
}
} }

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@@ -0,0 +1,69 @@
package com.cameleer.server.app.outbound;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.URI;
import java.net.UnknownHostException;
/**
* Validates outbound webhook URLs against SSRF pitfalls: rejects hosts that resolve to
* loopback, link-local, or RFC-1918 private ranges (and IPv6 equivalents).
*
* Per spec §17. The `cameleer.server.outbound-http.allow-private-targets` flag bypasses
* the check for dev environments where webhooks legitimately point at local services.
*/
@Component
public class SsrfGuard {
private final boolean allowPrivate;
public SsrfGuard(
@Value("${cameleer.server.outbound-http.allow-private-targets:false}") boolean allowPrivate
) {
this.allowPrivate = allowPrivate;
}
public void validate(URI uri) {
if (allowPrivate) return;
String host = uri.getHost();
if (host == null || host.isBlank()) {
throw new IllegalArgumentException("URL must include a host: " + uri);
}
if ("localhost".equalsIgnoreCase(host)) {
throw new IllegalArgumentException("URL host resolves to private or loopback range: " + host);
}
InetAddress[] addrs;
try {
addrs = InetAddress.getAllByName(host);
} catch (UnknownHostException e) {
throw new IllegalArgumentException("URL host does not resolve: " + host, e);
}
for (InetAddress addr : addrs) {
if (isPrivate(addr)) {
throw new IllegalArgumentException("URL host resolves to private or loopback range: " + host + " -> " + addr.getHostAddress());
}
}
}
private static boolean isPrivate(InetAddress addr) {
if (addr.isLoopbackAddress()) return true;
if (addr.isLinkLocalAddress()) return true;
if (addr.isSiteLocalAddress()) return true; // 10/8, 172.16/12, 192.168/16
if (addr.isAnyLocalAddress()) return true; // 0.0.0.0, ::
if (addr instanceof Inet6Address ip6) {
byte[] raw = ip6.getAddress();
// fc00::/7 unique-local
if ((raw[0] & 0xfe) == 0xfc) return true;
}
if (addr instanceof Inet4Address ip4) {
byte[] raw = ip4.getAddress();
// 169.254.0.0/16 link-local (also matches isLinkLocalAddress but doubled-up for safety)
if ((raw[0] & 0xff) == 169 && (raw[1] & 0xff) == 254) return true;
}
return false;
}
}

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@@ -1,6 +1,7 @@
package com.cameleer.server.app.outbound.config; package com.cameleer.server.app.outbound.config;
import com.cameleer.server.app.outbound.OutboundConnectionServiceImpl; import com.cameleer.server.app.outbound.OutboundConnectionServiceImpl;
import com.cameleer.server.app.outbound.SsrfGuard;
import com.cameleer.server.app.outbound.crypto.SecretCipher; import com.cameleer.server.app.outbound.crypto.SecretCipher;
import com.cameleer.server.app.outbound.storage.PostgresOutboundConnectionRepository; import com.cameleer.server.app.outbound.storage.PostgresOutboundConnectionRepository;
import com.cameleer.server.core.alerting.AlertRuleRepository; import com.cameleer.server.core.alerting.AlertRuleRepository;
@@ -31,7 +32,8 @@ public class OutboundBeanConfig {
public OutboundConnectionService outboundConnectionService( public OutboundConnectionService outboundConnectionService(
OutboundConnectionRepository repo, OutboundConnectionRepository repo,
AlertRuleRepository ruleRepo, AlertRuleRepository ruleRepo,
SsrfGuard ssrfGuard,
@Value("${cameleer.server.tenant.id:default}") String tenantId) { @Value("${cameleer.server.tenant.id:default}") String tenantId) {
return new OutboundConnectionServiceImpl(repo, ruleRepo, tenantId); return new OutboundConnectionServiceImpl(repo, ruleRepo, ssrfGuard, tenantId);
} }
} }

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@@ -0,0 +1,73 @@
package com.cameleer.server.app.outbound;
import org.junit.jupiter.api.Test;
import java.net.URI;
import java.util.Set;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
class SsrfGuardTest {
private final SsrfGuard guard = new SsrfGuard(false); // allow-private disabled by default
@Test
void rejectsLoopbackIpv4() {
assertThatThrownBy(() -> guard.validate(URI.create("https://127.0.0.1/webhook")))
.isInstanceOf(IllegalArgumentException.class)
.hasMessageContaining("private or loopback");
}
@Test
void rejectsLocalhostHostname() {
assertThatThrownBy(() -> guard.validate(URI.create("https://localhost:8080/x")))
.isInstanceOf(IllegalArgumentException.class);
}
@Test
void rejectsRfc1918Ranges() {
for (String url : Set.of(
"https://10.0.0.1/x",
"https://172.16.5.6/x",
"https://192.168.1.1/x"
)) {
assertThatThrownBy(() -> guard.validate(URI.create(url)))
.as(url)
.isInstanceOf(IllegalArgumentException.class);
}
}
@Test
void rejectsLinkLocal() {
assertThatThrownBy(() -> guard.validate(URI.create("https://169.254.169.254/latest/meta-data/")))
.isInstanceOf(IllegalArgumentException.class);
}
@Test
void rejectsIpv6Loopback() {
assertThatThrownBy(() -> guard.validate(URI.create("https://[::1]/x")))
.isInstanceOf(IllegalArgumentException.class);
}
@Test
void rejectsIpv6UniqueLocal() {
assertThatThrownBy(() -> guard.validate(URI.create("https://[fc00::1]/x")))
.isInstanceOf(IllegalArgumentException.class);
}
@Test
void acceptsPublicHttps() {
// DNS resolution happens inside validate(); this test relies on a public hostname.
// Use a literal public IP to avoid network flakiness.
// 8.8.8.8 is a public Google DNS IP — not in any private range.
assertThat(new SsrfGuard(false)).isNotNull();
guard.validate(URI.create("https://8.8.8.8/")); // does not throw
}
@Test
void allowPrivateFlagBypassesCheck() {
SsrfGuard permissive = new SsrfGuard(true);
permissive.validate(URI.create("https://127.0.0.1/")); // must not throw
}
}

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@@ -0,0 +1,67 @@
package com.cameleer.server.app.outbound.controller;
import com.cameleer.server.app.AbstractPostgresIT;
import com.cameleer.server.app.TestSecurityHelper;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.TestPropertySource;
import static org.assertj.core.api.Assertions.assertThat;
/**
* Dedicated IT that overrides the test-profile default `allow-private-targets=true`
* back to `false` so the SSRF guard's production behavior (reject loopback) is
* exercised end-to-end through the admin controller.
*
* Uses {@link DirtiesContext} to avoid polluting the shared context used by the
* other ITs which rely on the flag being `true` to hit WireMock on localhost.
*/
@TestPropertySource(properties = "cameleer.server.outbound-http.allow-private-targets=false")
@DirtiesContext
class OutboundConnectionSsrfIT extends AbstractPostgresIT {
@Autowired private TestRestTemplate restTemplate;
@Autowired private TestSecurityHelper securityHelper;
private String adminJwt;
@BeforeEach
void setUp() {
adminJwt = securityHelper.adminToken();
// Seed admin user row since users(user_id) is an FK target.
jdbcTemplate.update(
"INSERT INTO users (user_id, provider, email, display_name) VALUES (?, 'test', ?, ?) ON CONFLICT (user_id) DO NOTHING",
"test-admin", "test-admin@example.com", "test-admin");
jdbcTemplate.update("DELETE FROM outbound_connections WHERE tenant_id = 'default'");
}
@AfterEach
void cleanup() {
jdbcTemplate.update("DELETE FROM outbound_connections WHERE tenant_id = 'default'");
jdbcTemplate.update("DELETE FROM users WHERE user_id = 'test-admin'");
}
@Test
void rejectsLoopbackUrlOnCreate() {
String body = """
{"name":"evil","url":"https://127.0.0.1/abuse","method":"POST",
"tlsTrustMode":"SYSTEM_DEFAULT","auth":{}}""";
ResponseEntity<String> resp = restTemplate.exchange(
"/api/v1/admin/outbound-connections", HttpMethod.POST,
new HttpEntity<>(body, securityHelper.authHeaders(adminJwt)),
String.class);
assertThat(resp.getStatusCode()).isEqualTo(HttpStatus.BAD_REQUEST);
assertThat(resp.getBody()).isNotNull();
assertThat(resp.getBody()).contains("private or loopback");
}
}

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@@ -17,3 +17,5 @@ cameleer:
bootstraptokenprevious: old-bootstrap-token bootstraptokenprevious: old-bootstrap-token
infrastructureendpoints: true infrastructureendpoints: true
jwtsecret: test-jwt-secret-for-integration-tests-only jwtsecret: test-jwt-secret-for-integration-tests-only
outbound-http:
allow-private-targets: true