Security readout for executives and security teams
Plain-English summary
CGAL 5.1.1 can mishandle malformed Nef polygon input, causing an out-of-bounds read and type confusion that may lead to code execution. The business risk is highest where systems accept or process untrusted geometry files, especially through automated services or exposed upload workflows.
Executive priority
Prioritize remediation for internet-facing or partner-facing systems that process uploaded geometry files. For internal-only tools, schedule prompt patching after confirming exposure. The CVSS 10 score reflects severe impact potential, but current sources do not establish active exploitation.
Technical view
The flaw is in CGAL libcgal CGAL-5.1.1 Nef_S2/SNC_io_parser.h, involving SNC_io_parser::read_sface(), store_sm_boundary_item(), and Sloop_of boundary parsing. Sources describe CWE-129 out-of-bounds read leading to type confusion and possible code execution from attacker-provided malformed input.
Likely exposure
Exposure is likely limited to applications, services, or packaged distributions using CGAL/libcgal 5.1.1 and parsing untrusted Nef polygon or related geometry files. Systems that never process attacker-controlled geometry input are lower priority.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Talos reports that specially crafted malformed files can trigger the issue. Treat reachable file-processing paths as high risk, but do not assume exploitation is occurring without local evidence.
Researcher notes
Focus review on Nef polygon parsing paths and trust boundaries around file ingestion. The available bundle identifies the vulnerable parser functions and CWE-129 class, but does not provide complete fixed-version details. Avoid relying on CVSS network scope alone; validate actual application reachability.
Mitigation direction
- Inventory CGAL/libcgal deployments and identify version 5.1.1 usage.
- Apply vendor security updates from Debian, Gentoo, or the relevant package source.
- Check CGAL upstream or distribution guidance for fixed package versions.
- Restrict untrusted geometry file ingestion until affected components are updated.
- Add input handling safeguards around automated geometry parsing workflows.
Validation and detection
- Confirm whether applications link against CGAL/libcgal 5.1.1.
- Map all services that accept or batch-process geometry files.
- Verify installed packages include the relevant vendor security update.
- Review logs for unexpected crashes in CGAL-backed file processing.
- Confirm untrusted file parsing is isolated or disabled where updates lag.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-129: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-35635 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 10 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H3.96Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
10CriticalVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2020-1225CVE reference
- [debian-lts-announce] 20221206 [SECURITY] [DLA 3226-1] cgal security updateCVE reference · mailing-list
- GLSA-202305-34CVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Validation of Array Index
Improper Validation of Array Index represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.