Create README.md

README.md

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+---
+license: mit
+---
+
+# SD-CPP-001: stable-diffusion.cpp GGUFReader Process Crash PoC
+
+**Security Research — Responsible Disclosure**
+
+## Vulnerability
+
+Three input validation failures in `src/gguf_reader.hpp` (GGUFReader class) of [stable-diffusion.cpp](https://github.com/leejet/stable-diffusion.cpp) allow an attacker to crash any process loading a malformed GGUF file.
+
+| Bug | Line | Root Cause | Impact |
+|-----|------|-----------|--------|
+| 1 | 62 | `std::string key(key_len, '\0')` with no bound check | `std::length_error` uncaught -> `std::terminate()` |
+| 2 | 140 | `info.name.resize(name_len)` with no bound check | `std::bad_alloc` not caught by `catch(runtime_error)` |
+| 3 | 155 | `shape[3] *= shape[4]` signed int64 multiply | Undefined behavior (signed overflow) |
+
+**Commit**: d6dd6d7b555c233bb9bc9f20b4751eb8c9269743
+
+## Reproduction
+
+```bash
+python3 poc_sd_cpp_gguf_reader.py
+# Generates 3 PoC files (32-92 bytes each)
+
+# Build stable-diffusion.cpp from source
+git clone https://github.com/leejet/stable-diffusion.cpp
+cd stable-diffusion.cpp && mkdir build && cd build
+cmake .. && cmake --build . --config Debug
+
+# Trigger crash
+./bin/sd --model /path/to/poc_metadata_oob.gguf -p "test" -o /dev/null
+# Expected: "terminate called after throwing an instance of 'std::length_error'"
+```
+
+## Trigger Condition
+
+GGUFReader is a fallback parser invoked when `gguf_init_from_file()` fails (model.cpp:419). A GGUF file with version=999 triggers this fallback reliably. The fallback parser performs zero validation on length fields read from the file.
+
+## Suggested Fix
+
+Add upper-bound validation before string allocations and widen the catch block:
+
+```cpp
+// Line 62: bound key_len
+if (key_len > 65536) { LOG_ERROR("key_len too large"); return false; }
+
+// Line 214: catch all exceptions, not just runtime_error
+} catch (const std::exception& e) {
+```
+
+## Reporter
+
+Viridis Security (Justin Hart) — viridisnorthllc@gmail.com