CVE-2022-31018
📋 TL;DR
A denial-of-service vulnerability in Play Framework's forms library allows attackers to crash applications by sending deeply-nested JSON objects. This affects Play Framework versions 2.8.3 through 2.8.15 when using form binding methods with JSON data, causing OutOfMemoryError and potential process termination.
💻 Affected Systems
- Play Framework
📦 What is this software?
Play Framework by Lightbend
⚠️ Risk & Real-World Impact
Worst Case
Application crashes completely, causing service disruption until manually restarted, with potential data loss for in-memory sessions.
Likely Case
Application becomes unresponsive or crashes, requiring restart and causing temporary service outage.
If Mitigated
Application remains stable with proper JSON depth limits or alternative body parsers in place.
🎯 Exploit Status
Exploitation requires sending specially crafted JSON payloads to vulnerable endpoints. No authentication needed if endpoints are publicly accessible.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.8.16
Vendor Advisory: https://github.com/playframework/playframework/security/advisories/GHSA-v8x6-59g4-5g3w
Restart Required: Yes
Instructions:
1. Update Play Framework dependency to version 2.8.16 or later. 2. Update build configuration (build.sbt for Scala, pom.xml for Java). 3. Rebuild and redeploy application. 4. Restart application server.
🔧 Temporary Workarounds
Use alternative body parser
allSwitch from default body parser to one that doesn't parse JSON if application doesn't need JSON support
// In Scala: Use other body parsers like parse.tolerantText
// In Java: Use BodyParser.anyContent other than JSON
Configure JSON depth limit manually
allManually implement JSON parsing with depth limits before form binding
// Implement custom JSON parser with depth checking before Form.bindFromRequest
🧯 If You Can't Patch
- Implement WAF rules to block requests with deeply-nested JSON structures
- Use rate limiting and request size limits to mitigate impact
🔍 How to Verify
Check if Vulnerable:
Check Play Framework version in build configuration. If using 2.8.3-2.8.15 and using Form.bindFromRequest with JSON, application is vulnerable.Check Version:
sbt 'show playVersion' for Scala, or check pom.xml for Java projectsVerify Fix Applied:
Verify Play Framework version is 2.8.16 or later in dependencies. Test with nested JSON payloads to confirm application doesn't crash.📡 Detection & Monitoring
Log Indicators:
- OutOfMemoryError in application logs
- Application crash/restart events
- Unusually large JSON payloads in request logs
Network Indicators:
- Requests with deeply-nested JSON structures
- Sudden drop in application availability
SIEM Query:
source="application.logs" AND ("OutOfMemoryError" OR "java.lang.OutOfMemoryError") AND "play.api.data.Form"🔗 References
- https://github.com/playframework/playframework/pull/11301
- https://github.com/playframework/playframework/releases/tag/2.8.16
- https://github.com/playframework/playframework/security/advisories/GHSA-v8x6-59g4-5g3w
- https://github.com/playframework/playframework/pull/11301
- https://github.com/playframework/playframework/releases/tag/2.8.16
- https://github.com/playframework/playframework/security/advisories/GHSA-v8x6-59g4-5g3w
