CVE-2020-28630 in CGAL
Summary
by MITRE • 04/18/2022
Multiple code execution vulnerabilities exists in the Nef polygon-parsing functionality of CGAL libcgal CGAL-5.1.1. A specially crafted malformed file can lead to an out-of-bounds read and type confusion, which could lead to code execution. An attacker can provide malicious input to trigger any of these vulnerabilities. An oob read vulnerability exists in Nef_S2/SNC_io_parser.h SNC_io_parser::read_sedge() seh->snext().
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Analysis
by VulDB Data Team • 04/21/2022
The CVE-2020-28630 vulnerability represents a critical security flaw within the Computational Geometry Algorithms Library (CGAL) version 5.1.1, specifically affecting the Nef polygon-parsing functionality. This vulnerability resides in the libcgal component of CGAL and constitutes a significant threat to systems that process geometric data through polygon operations. The flaw manifests as multiple code execution vulnerabilities that can be exploited through carefully crafted malformed input files, making it particularly dangerous for applications that handle untrusted geometric data from external sources.
The technical implementation of this vulnerability involves an out-of-bounds read condition within the Nef_S2/SNC_io_parser.h file, specifically within the SNC_io_parser::read_sedge() function. The problematic code path involves the seh->snext() operation where the software attempts to access memory beyond the allocated bounds of a data structure. This out-of-bounds read creates a type confusion scenario that can be leveraged by attackers to manipulate memory layout and potentially execute arbitrary code. The vulnerability stems from inadequate input validation and bounds checking within the polygon parsing routines, allowing maliciously constructed geometric data to trigger memory corruption.
The operational impact of CVE-2020-28630 extends beyond simple code execution, as it represents a complete compromise of system integrity when exploited. Systems utilizing CGAL for geometric computations, particularly those processing external or user-provided polygon data, become vulnerable to remote code execution attacks. This vulnerability affects applications across multiple domains including CAD software, geographic information systems, computer graphics applications, and any system performing geometric operations that rely on the affected CGAL components. The attack vector is particularly concerning as it requires only the ability to provide malicious input to the polygon parsing functionality, making it accessible to attackers who can influence data processing workflows.
Security mitigations for this vulnerability should focus on immediate patching of affected CGAL versions, with organizations implementing comprehensive input validation and sanitization for all polygon data processing workflows. The recommended approach includes upgrading to patched versions of CGAL 5.1.1 or later, implementing strict bounds checking in custom applications that interface with CGAL, and deploying defensive programming techniques such as address space layout randomization and stack canaries. Additionally, organizations should consider network segmentation and access controls to limit exposure of systems that process polygon data, while monitoring for suspicious file processing activities that might indicate exploitation attempts. This vulnerability aligns with CWE-125 Out-of-bounds Read and CWE-476 NULL Pointer Dereference patterns, and represents a significant concern under ATT&CK framework category T1059 Command and Scripting Interpreter for code execution capabilities.