go.large_response_memory

Stability Medium

Detects HTTP response body reads without size limits, which can exhaust memory.

Why It Matters

Unbounded response reads cause:

• OOM crashes — Malicious or broken servers return huge responses
• DoS vulnerability — Attackers control response size
• Resource exhaustion — Memory spikes affect other requests

Example

// ❌ Before (unbounded)
resp, _ := http.Get(url)
body, _ := io.ReadAll(resp.Body) // Could be gigabytes!

// ✅ After (bounded)
resp, _ := http.Get(url)
body, _ := io.ReadAll(io.LimitReader(resp.Body, 10*1024*1024)) // 10MB max

What Unfault Detects

• io.ReadAll(resp.Body) without limits
• ioutil.ReadAll() without Content-Length check
• JSON decoding without size limits

Auto-Fix

Unfault adds io.LimitReader:

const maxResponseSize = 10 * 1024 * 1024 // 10MB

body, err := io.ReadAll(io.LimitReader(resp.Body, maxResponseSize))

Related Rules

• go.unbounded_memory
• python.large_response_memory