All news with #go tag

Go clients, HTTP/2 PING floods, and ENHANCE_YOUR_CALM

🔍 This post investigates why Cloudflare returned ENHANCE_YOUR_CALM for internal HTTP/2 traffic and traces the issue to an easy-to-make Go client behavior. An incorrect pattern where a response is closed without being fully read caused the Go HTTP/2 library to emit RST_STREAM and PING frames in quick succession, triggering PING-flood mitigations. The fix: always drain response bodies (for example, io.Copy(io.Discard, resp.Body)) before calling Close().

How Cloudflare Found and Fixed a Bug in Go's ARM64 Compiler

🔍 Cloudflare engineers describe discovering a rare race condition in the Go arm64 compiler that caused goroutine stack-unwinding crashes in production. They traced sporadic fatal panics and segfaults to async preemption interrupting a split stack-pointer adjustment, leaving an invalid stack frame. A minimal reproducer showed the assembler could split a large ADD into multiple instructions, creating a one-instruction window where preemption caused unwinder corruption. The issue was fixed upstream in go1.23.12, go1.24.6, and go1.25.0.

ShadowV2 Botnet Targets Misconfigured AWS Docker Containers

⚠️ Researchers at Darktrace disclosed ShadowV2, a DDoS-focused botnet that exploits misconfigured Docker daemons on AWS EC2 instances to deploy a Go-based RAT and enlist hosts as attack nodes. The campaign uses a Python spreader to spawn an Ubuntu setup container, build a custom image, and run an ELF payload that checks in with a Codespaces-hosted C2. Operators leverage HTTP/2 Rapid Reset floods, a Cloudflare UAM bypass via ChromeDP, and a FastAPI/Pydantic operator API, signaling a modular DDoS-for-hire service.