Security readout for executives and security teams
Plain-English summary
CVE-2021-35000 is a low-severity local information disclosure flaw in OpenBSD 6.9 kernel multicast routing code. A person who already can run low-privileged code may read uninitialized kernel memory. Alone, impact is limited, but leaked kernel data can help chain with other bugs.
Executive priority
Treat as a low standalone risk, but do not ignore on shared or high-value OpenBSD systems. The business concern is attack-chain support: local attackers may use leaked kernel data to make more serious vulnerabilities easier to exploit.
Technical view
The flaw is CWE-908 in OpenBSD Kernel multicast routing: memory is accessed before proper initialization. CVSS 3.0 is 3.3, local, low complexity, low privileges required, confidentiality impact only. ZDI states it may assist privilege escalation when combined with other vulnerabilities.
Likely exposure
Exposure is limited to affected OpenBSD Kernel installations identified in the source bundle, specifically OpenBSD 6.9. Risk is higher on multi-user systems, systems running untrusted local code, or hosts where local compromise could enable broader kernel-level attack chains.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Exploitation requires existing low-privileged local code execution. ZDI says the information leak can be used with other vulnerabilities to escalate privileges and execute code in kernel context.
Researcher notes
Evidence is narrow: affected product is OpenBSD Kernel, version OpenBSD 6.9, with ZDI-CAN-16112 as the research advisory lineage. No public source in the bundle names active exploitation, a patch version, or broader affected versions.
Mitigation direction
- Check OpenBSD security advisories for fixed versions or vendor-recommended mitigations.
- Prioritize upgrading OpenBSD 6.9 systems if vendor guidance identifies a fixed release.
- Restrict local shell access and untrusted code execution on affected systems.
- Harden multi-user OpenBSD hosts where kernel information leaks increase attack-chain risk.
Validation and detection
- Inventory OpenBSD systems and identify any running OpenBSD 6.9.
- Confirm whether affected hosts permit untrusted local users or workloads.
- Review OpenBSD advisory history for the vendor-fixed kernel version.
- Monitor EDR, audit, and system logs for suspicious local privilege-escalation behavior.
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-908: 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-2021-35000 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
- Low
- CVSS
- 3.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
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:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N1.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
3.3LowVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- ZDI-22-012CVE reference · x_research-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.
Use of Uninitialized Resource
Use of Uninitialized Resource represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.