CVE-2020-28615 is a medium-severity vulnerability affecting the CGAL Project's libcgal library version 5.1.1, specifically within the Nef polygon-parsing functionality. The root cause is an improper validation of array indices (CWE-129) in the code handling polygon parsing, particularly in the Nef_S2/SNC_io_parser.h file within the read_vertex() function. This improper validation leads to out-of-bounds (OOB) reads and type confusion errors when processing specially crafted malformed input files. The OOB read occurs when the code attempts to access elements beyond the bounds of an array or container, in this case via the call vh->shalfedges_last(). Such memory access violations can corrupt program state, potentially allowing an attacker to execute arbitrary code. The vulnerability is triggered by supplying maliciously crafted input files to the vulnerable parsing functionality, which does not require prior authentication or user interaction beyond feeding the malformed file to the system. Although no known exploits have been reported in the wild, the vulnerability presents a risk of remote code execution if an attacker can convince a target system to process a malicious file. The absence of a CVSS score requires an assessment based on the impact on confidentiality, integrity, and availability, ease of exploitation, and scope of affected systems. The vulnerability affects a specialized computational geometry library used in applications that rely on CGAL for polygon and geometric data processing. The technical details indicate that the flaw resides in a core parsing routine, making any software dependent on this library potentially vulnerable if it processes untrusted input files. The vulnerability was publicly disclosed in April 2022, with no patch links provided in the source data, suggesting that users should verify the availability of updates from the CGAL project or apply mitigations to prevent exploitation.

For European organizations, the impact of this vulnerability depends largely on the extent to which CGAL libcgal 5.1.1 is used within their software stacks. Organizations involved in CAD, GIS, scientific computing, or any domain requiring advanced computational geometry processing may incorporate CGAL. Exploitation could lead to unauthorized code execution, resulting in potential data breaches, system compromise, or disruption of critical services. This could affect intellectual property confidentiality, integrity of geometric data, and availability of applications relying on CGAL. Given that the vulnerability can be triggered by processing malicious files, supply chain risks exist if untrusted or external data sources feed into vulnerable systems. The lack of authentication or user interaction requirements means automated or remote exploitation is feasible if file ingestion is exposed. European critical infrastructure sectors such as manufacturing, aerospace, and research institutions using CGAL-based tools could face operational disruptions or espionage risks. Additionally, organizations processing large volumes of geometric data from external partners or customers may be exposed to targeted attacks leveraging this vulnerability.

1. Verify and apply any official patches or updates released by the CGAL Project addressing CVE-2020-28615. If no patch is available, consider upgrading to a later, fixed version of libcgal. 2. Implement strict input validation and sanitization on all files processed by CGAL-based applications, rejecting malformed or suspicious polygon data before parsing. 3. Employ sandboxing or containerization techniques to isolate the CGAL processing environment, limiting the impact of potential code execution. 4. Monitor and restrict file sources, especially from untrusted or external origins, to reduce the risk of malicious input. 5. Conduct code audits and static analysis on custom software integrating CGAL to identify and remediate unsafe usage patterns. 6. Use runtime protections such as Address Space Layout Randomization (ASLR), Data Execution Prevention (DEP), and Control Flow Integrity (CFI) to mitigate exploitation impact. 7. Maintain up-to-date intrusion detection and prevention systems capable of detecting anomalous behavior related to malformed polygon file processing. 8. Educate developers and system administrators about the risks of processing untrusted geometric data and the importance of timely patching.