nu1lp7r/mfv-darknet-parse-route-oob

PoC: pjreddie/darknet — parse_route() Unchecked Layer Index (CWE-129)

Vulnerability

pjreddie/darknet is the original Darknet neural network framework. Its parse_route() function in src/parser.c reads layer indices from .cfg files via atoi() and uses them to index net->layers[index] without checking index >= 0 && index < net->n.

Affected Code

• File: src/parser.c (lines 615-619)
• Function: parse_route()
• Root cause: index = atoi(l) used as net->layers[index].outputs with no bounds check

Impact

A crafted .cfg file with layers=999999 in a [route] section causes darknet to read past the allocated layers array when loading the network configuration. This affects any service that parses user-supplied darknet .cfg files.

Reproduction

Build darknet with AddressSanitizer:

git clone https://github.com/pjreddie/darknet.git
cd darknet
sed -i 's/^CFLAGS=/CFLAGS=-fsanitize=address -g /' Makefile
make -j$(nproc)

Then run with the malicious config:

./darknet yolo test poc_malicious.cfg

Expected: ASan SEGV in parse_route (src/parser.c:1087)

Files

• poc_malicious.cfg — crafted darknet config with layers=999999
• parser.c — real source file from pjreddie/darknet showing vulnerable code

Suggested Fix

// parser.c, after line 617:
if (index < 0 || index >= net->n) {
    error("Invalid layer index in route layer");
}