# heap-buffer-overflow in onnx-ort-format (id:000023,sig:06,src:000011,time:17181566,execs:110105142,op:havoc,rep:1)

**Severity:** high
**CWE:** CWE-122
**Target:** onnx-ort-format
**Generated:** 2026-03-01

## Summary

heap-buffer-overflow in onnx-ort-format (id:000023,sig:06,src:000011,time:17181566,execs:110105142,op:havoc,rep:1). See ASAN output below for details.

## Reproduction

```bash
chmod +x reproduce.sh
./reproduce.sh
```

Or manually:
```bash
# Build target with ASAN
# Run: <target> poc.ort
```

## PoC File

- `poc.ort` (143 bytes)

## ASAN Output

```
Testing: /home/rammdaeus/huntr/fuzz-output/onnx-ort-format/main/crashes/id:000023,sig:06,src:000011,time:17181566,execs:110105142,op:havoc,rep:1 (143 bytes)
=================================================================
==3240144==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7aa58f749384 at pc 0x7e759513fae1 bp 0x7ffd7d7ad4e0 sp 0x7ffd7d7ad4d0
READ of size 4 at 0x7aa58f749384 thread T0
    #0 0x7e759513fae0 in MlasSgemmTransposePackB(float*, float const*, unsigned long, unsigned long, unsigned long) (/home/rammdaeus/huntr/libs/onnx/libonnxruntime.so.1+0x3d3fae0) (BuildId: 06133089d904988c5bacaadc701d1137241257f4)
    #1 0x7e7595140f05 in MlasSgemmOperation(CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, unsigned long, unsigned long, unsigned long, float, float const*, unsigned long, float const*, unsigned long, float, float*, unsigned long) (/home/rammdaeus/huntr/libs/onnx/libonnxruntime.so.1+0x3d40f05) (BuildId: 06133089d904988c5bacaadc701d1137241257f4)
    #2 0x7e75951426a6 in MlasSgemmThreaded(long, long, CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, unsigned long, unsigned long, unsigned long, MLAS_SGEMM_DATA_PARAMS const*, long) (/home/rammdaeus/huntr/libs/onnx/libonnxruntime.so.1+0x3d426a6) (BuildId: 06133089d904988c5bacaadc701d1137241257f4)
    #3 0x7e7595142928 in MlasGemmBatch(CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, unsigned long, unsigned long, unsigned long, MLAS_SGEMM_DATA_PARAMS const*, unsigned long, onnxruntime::concurrency::ThreadPool*)::{lambda(long)#1}::operator()(long) const (/home/rammdaeus/huntr/libs/onnx/libonnxruntime.so.1+0x3d42928) (BuildId: 06133089d904988c5bacaadc701d1137241257f4)
    #4 0x7e75951449fa in __invoke_impl<void, MlasGemmBatch(CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, size_t, size_t, size_t, const MLAS_SGEMM_DATA_PARAMS*, size_t, MLAS_THREADPOOL*)::<lambda(ptrdiff_t)>&, long int> /usr/include/c++/15/bits/invoke.h:63
    #5 0x7e7595144872 in __invoke_r<void, MlasGemmBatch(CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, size_t, size_t, size_t, const MLAS_SGEMM_DATA_PARAMS*, size_t, MLAS_THREADPOOL*)::<lambda(ptrdiff_t)>&, long int> /usr/include/c++/15/bits/invoke.h:113
    #6 0x7e75951445b4 in _M_invoke /usr/include/c++/15/bits/std_function.h:292
    #7 0x7e7592821fcf in std::function<void (long)>::operator()(long) const /usr/include/c++/15/bits/std_function.h:593
    #8 0x7e7595603116 in MlasTrySimpleParallel(onnxruntime::concurrency::ThreadPool*, long, std::function<void (long)> const&) /home/rammdaeus/gor/hunting/targets/onnxruntime/onnxruntime/core/mlas/lib/threading.cpp:71
    #9 0x7e7595142ead in MlasGemmBatch(CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, unsigned long, unsigned long, unsigned long, MLAS_SGEMM_DATA_PARAMS const*, unsigned long, onnxruntime::concurrency::ThreadPool*) /home/rammdaeus/gor/hunting/targets/onnxruntime/onnxruntime/core/mlas/lib/sgemm.cpp:1629
    #10 0x7e75945747ae in MlasGemm(CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, unsigned long, unsigned long, unsigned long, MLAS_SGEMM_DATA_PARAMS const&, onnxruntime::concurrency::ThreadPool*) /
```

## Impact

Memory corruption vulnerability reachable by processing a malformed onnx-ort-format file.
An attacker could craft a malicious file and distribute it to cause denial of service
or potentially leak sensitive heap data.