Security readout for executives and security teams
Plain-English summary
This flaw can let software trust a certificate chain that should have failed verification. In business terms, a system depending on vulnerable LibreSSL or unpatched OpenBSD certificate validation may accept an untrusted peer, undermining TLS-based identity checks and authentication decisions.
Executive priority
Treat as urgent for externally exposed or certificate-authenticated services. The issue can weaken identity assurance, so remediation should focus first on systems where a trusted certificate directly gates access, service-to-service communication, or customer-facing security controls.
Technical view
CVE-2021-46880 is a CWE-295 certificate validation flaw in LibreSSL x509/x509_verify.c before 3.4.2 and OpenBSD before 7.0 errata 006. The CVE states that an error for an unverified certificate chain is sometimes discarded, creating an authentication bypass condition.
Likely exposure
Exposure is most likely in systems, applications, appliances, or OS images using LibreSSL before 3.4.2 or OpenBSD 7.0 without errata 006, especially where certificate-chain verification controls authentication or trust.
Exploitation context
The provided sources and KEV status do not show confirmed active exploitation. The risk is still high because the flaw is network-reachable, requires no privileges or user interaction, and can affect certificate-based trust decisions.
Researcher notes
Evidence identifies the bug class and affected upstream code, but the supplied affected-product data is incomplete. Do not assume all OpenSSL-compatible consumers are affected; validate actual LibreSSL linkage, OS patch level, and vendor-specific advisory status.
Mitigation direction
- Upgrade LibreSSL to 3.4.2 or later where used.
- Apply OpenBSD 7.0 errata 006 or move to a supported patched release.
- Check vendor advisories for appliances or products bundling LibreSSL.
- Prioritize systems using TLS client authentication or certificate-based trust decisions.
Validation and detection
- Inventory hosts, containers, and appliances for LibreSSL versions below 3.4.2.
- Confirm OpenBSD 7.0 systems have errata 006 applied.
- Review application dependency manifests for bundled or statically linked LibreSSL.
- Check vendor advisories for product-specific affected versions and fixed releases.
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-295: 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-46880 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
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-3.4.2-relnotes.txtCVE reference
- https://github.com/openbsd/src/commit/3f851282810fa0ab4b90b3b1ecec2e8717ef16f8CVE reference
- https://ftp.openbsd.org/pub/OpenBSD/patches/7.0/common/006_x509.patch.sigCVE reference
- https://security.netapp.com/advisory/ntap-20230517-0006/CVE reference
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 Certificate Validation
Improper Certificate Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.