A heap-based out-of-bounds read vulnerability in Open CASCADE Technology (OCCT) V8_0_0_rc5 poses a risk of application denial of service or information disclosure via malicious STL files.

The vulnerability exists in the RWStl_Reader::ReadAscii function within the STL ASCII file parser, where buffers from Standard_ReadLineBuffer::ReadLine are not validated for length. An attacker with local access, or one who can convince a user to open a crafted STL file, can trigger an out-of-bounds read.

The exploitation of this vulnerability could result in system crashes or the disclosure of sensitive memory contents, potentially impacting the availability and confidentiality of engineering or CAD workflows. With a CVSS score of 7.1, the risk is categorized as High, reflecting the potential for significant disruption to business operations that rely on OCCT-based software.

Immediate Action: Users should restrict the opening of untrusted STL files from unknown sources and await an official security update from the vendor.

Proactive Monitoring: Monitor system logs for application crashes or abnormal memory usage patterns associated with the parsing of 3D model files.

Compensating Controls: Deploy endpoint security solutions configured to scan incoming files for malformed structures, which may mitigate the risk of processing malicious STL data.

Public Exploit Available: Yes — a public proof-of-concept exists as documented in the referenced GitHub Gist.

Given the availability of a public proof-of-concept, users of Open CASCADE Technology V8_0_0_rc5 should exercise extreme caution when handling untrusted 3D files. We strongly recommend tracking the vendor advisory for patch availability and applying the update immediately upon release to remediate the underlying memory safety flaw.