admesh normals.c stl_check_normal_vector heap-based overflow

A security flaw has been discovered in admesh up to 0.98.5. This issue affects the function stl_check_normal_vector of the file src/normals.c. Performing a manipulation results in heap-based buffer overflow. The attack must be initiated from a local position. The exploit has been released to the public and may be used for attacks. It looks like this product is not really maintained anymore.

An improper array index validation vulnerability exists in the stl_fix_normal_directions functionality of ADMesh Master Commit 767a105 and v0.98.4. A specially-crafted stl file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.

ADMesh through 0.98.4 has a heap-based buffer over-read in stl_update_connects_remove_1 (called from stl_remove_degenerate) in connect.c in libadmesh.a.