CVE-2025-48075
📋 TL;DR
A denial-of-service vulnerability in Go's Fiber web framework allows attackers to crash applications by sending specially crafted requests with negative array indices. This affects all applications using fiber.Ctx.BodyParser functionality in vulnerable versions, potentially making services unavailable.
💻 Affected Systems
- Go Fiber web framework
📦 What is this software?
Fiber by Gofiber
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage for affected endpoints, requiring application restart and potentially causing cascading failures in dependent systems.
Likely Case
Targeted DoS attacks against specific endpoints using BodyParser, causing intermittent service disruptions.
If Mitigated
Minimal impact with proper request validation, rate limiting, and monitoring in place.
🎯 Exploit Status
Simple HTTP request with negative array index can trigger the panic
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.52.7
Vendor Advisory: https://github.com/gofiber/fiber/security/advisories/GHSA-hg3g-gphw-5hhm
Restart Required: Yes
Instructions:
Update Go dependencies: go get github.com/gofiber/fiber/v2@v2.52.7
Rebuild and redeploy application
Test BodyParser functionality
🔧 Temporary Workarounds
Input validation middleware
allAdd middleware to validate array indices before BodyParser processes them
Rate limiting
allImplement request rate limiting to reduce DoS impact
🧯 If You Can't Patch
- Implement WAF rules to block requests with negative array indices
- Deploy application behind reverse proxy with request filtering
🔍 How to Verify
Check if Vulnerable:
Check go.mod for fiber version: grep 'github.com/gofiber/fiber/v2' go.modCheck Version:
go list -m github.com/gofiber/fiber/v2Verify Fix Applied:
Verify version is 2.52.7 or later: go list -m github.com/gofiber/fiber/v2📡 Detection & Monitoring
Log Indicators:
- Application panic logs mentioning BodyParser
- Unusual HTTP 500 errors on BodyParser endpoints
- Stack traces with fiber.Ctx.BodyParser
Network Indicators:
- HTTP requests with array parameters containing negative indices
- Sudden spike in failed requests to specific endpoints
SIEM Query:
source="application.logs" AND ("panic" OR "BodyParser") AND "fiber"