COMP-1149 added HttpClientAddressResolver in RateLimiterFilter

[munishchouhan]

Summary

Fixed IP address spoofing vulnerability where attackers could bypass rate limiting by sending arbitrary X-Forwarded-For headers. The rate limiter now uses socket addresses by default (secure) with opt-in support for trusted proxy headers when deployed behind AWS ALB.

Vulnerability

The rate limiter previously trusted client-supplied X-Forwarded-For headers without validation, allowing attackers to bypass rate limits by spoofing different IP addresses:

# Attack: Send 1000 requests with different spoofed IPs
for i in {1..1000}; do
    curl -H "X-Forwarded-For: 192.168.1.$i" http://wave.example.com/v2/
done
# Each request got separate rate limit → attack succeeds

Solution

Implemented custom SecureHttpClientAddressResolver that takes the rightmost IP from comma-separated X-Forwarded-For headers:

• Default Mode (Secure): Uses socket address directly, ignoring all headers
• ALB Mode (Opt-in): Takes rightmost IP from X-Forwarded-For (the one ALB added)

Key Implementation

@Override
String resolve(HttpRequest request) {
    // Get IP from Micronaut's default logic
    final String resolvedIp = super.resolve(request)

    if (!resolvedIp || !resolvedIp.contains(',')) {
        return resolvedIp  // Single IP - return as is
    }

    // SECURITY FIX: Take the RIGHTMOST IP (added by ALB)
    // X-Forwarded-For: <spoofed-ip>, <real-client-ip>
    // Returns: <real-client-ip>
    final String[] ips = resolvedIp.split(',')
    return ips[ips.length - 1].trim()
}

Why Rightmost IP?

When behind ALB, the X-Forwarded-For header contains:

• Leftmost IP: Client-supplied (can be spoofed)
• Rightmost IP: Added by ALB (trustworthy)

Example:

Client sends: X-Forwarded-For: 192.168.1.1 (spoofed)
ALB prepends: X-Forwarded-For: 192.168.1.1, 203.0.113.5 (real)
Wave uses: 203.0.113.5 ✓ (rightmost = secure)

Changes

Core Files

• SecureHttpClientAddressResolver.groovy (NEW) (src/main/groovy/io/seqera/wave/util/SecureHttpClientAddressResolver.groovy):

  • Custom resolver that takes rightmost IP from X-Forwarded-For
  • Extends Micronaut's DefaultHttpClientAddressResolver
  • Replaces default resolver when ALB profile is enabled
  • Prevents IP spoofing by ignoring client-supplied IPs

• ContainerController.groovy & RegistryProxyController.groovy:

  • Already inject and use HttpClientAddressResolver
  • No code changes needed - automatically use secure resolver

• RateLimiterFilter.groovy (src/main/groovy/io/seqera/wave/filter/RateLimiterFilter.groovy):

  • Already injects and uses HttpClientAddressResolver
  • No code changes needed

Configuration

• application-alb.yml (NEW) (src/main/resources/application-alb.yml):
  • Profile for AWS ALB deployments
  • Configures client-address-header: X-Forwarded-For
  • Includes security warnings about when to enable

Tests

• RateLimiterFilterTest.groovy (NEW) (src/test/groovy/io/seqera/wave/filter/RateLimiterFilterTest.groovy):
  • 4 comprehensive unit tests (100% passing)
  • Verifies spoofed headers are ignored by default
  • Verifies X-Forwarded-For is trusted only in ALB mode

Documentation

• docs/configuration.md: Added security section explaining ALB profile usage

Security Benefits

Default Mode (Secure by Default)

Client sends: X-Forwarded-For: 1.2.3.4
Socket IP: 127.0.0.1
Rate limit key: 127.0.0.1 ✓ (spoofed header ignored)

ALB Mode (When Configured)

MICRONAUT_ENVIRONMENTS=alb

Real Client (1.2.3.4) → ALB → Wave
Socket IP: 10.0.1.50 (ALB's IP)
X-Forwarded-For: 1.2.3.4 (real client, added by ALB)
Rate limit key: 1.2.3.4 ✓ (header trusted from ALB)

[pditommaso]

What's prevent to use this always ?

[munishchouhan]

I am concerned that, it will add performance overhead on each request, I will dig more to see what is better

[munishchouhan]

tested in dev:

wave % for i in {1..110}; do
      curl -H "X-Forwarded-For: 10.99.88.$i" \
           -X POST https://wave.dev-seqera.io/v1alpha2/container \
           -H "Content-Type: application/json" \
           -d '{"containerImage": "ubuntu:22.04"}' \
           -s -o /dev/null -w "Request $i: %{http_code}\n"
  done
.
.
.
.
Request 100: 200
Request 101: 200
Request 102: 200
Request 103: 200
Request 104: 429
Request 105: 429
Request 106: 429
Request 107: 429
Request 108: 429
Request 109: 429
Request 110: 429

[munishchouhan]

run again:

wave % for i in {1..110}; do
      curl -H "X-Forwarded-For: 10.99.88.$i" \
           -X POST https://wave.dev-seqera.io/v1alpha2/container \
           -H "Content-Type: application/json" \
           -d '{"containerImage": "ubuntu:22.04"}' \
           -s -o /dev/null -w "Request $i: %{http_code}\n"
  done
Request 1: 429
Request 2: 429
Request 3: 429
Request 4: 429

[munishchouhan]

if removed alb env:

wave % for i in {1..110}; do
      curl -H "X-Forwarded-For: 10.99.88.$i" \
           -X POST https://wave.dev-seqera.io/v1alpha2/container \
           -H "Content-Type: application/json" \
           -d '{"containerImage": "ubuntu:22.04"}' \
           -s -o /dev/null -w "Request $i: %{http_code}\n"
  done
Request 1: 200
Request 2: 200
Request 3: 200
Request 4: 200

Request 5: 200
Request 6: 200