CVE-2026-45047 — bird-lg-go

Summary

The apiHandler (and similarly webHandlerTelegramBot) processes user-provided JSON payloads by directly using json.NewDecoder(r.Body).Decode(&request) without restricting the maximum read size. An unauthenticated remote attacker can stream an extremely large, endless JSON payload (e.g., several Gigabytes of padding) over a single TCP connection. Because Go's JSON decoder attempts to allocate memory for the entire parsed structure, this rapidly exhausts the host's physical RAM or container limits, leading to an unrecoverable fatal error: runtime: out of memory.

This causes the Linux OOM Killer to instantly terminate the entire bird-lg-go daemon, resulting in a severe Remote Denial of Service (RDoS).

Details

In api.go:

func apiHandler(w http.ResponseWriter, r *http.Request) {
    var request apiRequest
    // VULNERABILITY: No http.MaxBytesReader protection before JSON decode
    err := json.NewDecoder(r.Body).Decode(&request) 
    // ...