How the CVE Works
The vulnerability in Apollo Router stems from inefficient handling of deeply nested and reused named fragments in GraphQL queries. The query planner’s optimization logic, designed to skip redundant computations, fails when processing such fragments. This forces the planner to repeatedly evaluate the same selections, exponentially increasing CPU and memory usage. Since no timeout mechanism exists, malicious queries can exhaust thread pools, leading to a complete denial of service. Attackers craft queries with recursive fragment references, bypassing optimizations and overwhelming the router.
DailyCVE Form
Platform: Apollo Router
Version: <1.61.2, <2.1.1
Vulnerability: DoS
Severity: Critical
Date: 2023-XX-XX
What Undercode Say:
Exploitation:
- Craft a malicious GraphQL query with nested fragments:
query { ...FragmentA } fragment FragmentA on Query { ...FragmentB } fragment FragmentB on Query { ...FragmentA Recursive reference } - Send repeated requests to the Apollo Router endpoint.
Detection:
- Monitor CPU spikes during query planning.
- Log queries with excessive fragment depth:
grep -E '....+{' /var/log/apollo/router.log
Protection:
- Patch: Upgrade to Apollo Router 1.61.2 or 2.1.1.
2. Rate Limiting: Enforce query complexity limits:
apollo-config.yml query_planning: optimization_limit: 1000
3. Persisted Queries: Restrict execution to pre-approved queries.
Mitigation Commands:
- Block abusive IPs via firewall:
iptables -A INPUT -p tcp --dport 4000 -m string --string "FragmentA" --algo bm -j DROP
- Enable GraphQL query cost analysis:
const { createApolloQueryValidationPlugin } = require('graphql-cost-analysis');
Debugging:
- Profile query planning time:
curl -X POST -H "Content-Type: application/json" -d '{"query":"{__typename}"}' http://localhost:4000 | jq '.extensions.queryPlanning'
References:
- Apollo Router Patches: GitHub Commit
- GraphQL DoS Mitigation: OWASP Guide
References:
Reported By: https://github.com/advisories/GHSA-94hh-jmq8-2fgp
Extra Source Hub:
Undercode
