Security readout for executives and security teams
Plain-English summary
CVE-2021-34999 is a local information disclosure flaw in the OpenBSD 6.9 kernel multicast routing code. A low-privileged local attacker could read sensitive information. On its own the rated impact is low, but ZDI notes the leak could support chaining with other vulnerabilities toward kernel-level compromise.
Executive priority
Treat this as low standalone urgency but relevant to defense-in-depth. Prioritize shared or high-value OpenBSD 6.9 systems, especially where local accounts or workloads are exposed to untrusted users.
Technical view
The issue is uninitialized memory exposure in OpenBSD kernel multicast routing, mapped to CWE-908. The CVSS v3.0 vector is local, low complexity, low privileges, no user interaction, changed scope, low confidentiality impact, and no integrity or availability impact.
Likely exposure
Exposure appears limited to systems running OpenBSD 6.9 where an attacker can execute low-privileged local code. The provided sources do not identify other affected versions, internet-exposed attack paths, or remote exploitation.
Exploitation context
The sources do not report active exploitation, and the CVE is not listed as KEV in the provided bundle. Exploitation requires prior local code execution, making this mainly relevant for shared systems, compromised accounts, or chained attacks.
Researcher notes
Evidence is narrow: the bundle names OpenBSD 6.9 Kernel and ZDI-CAN-14540/ZDI-22-073. No exploit code, patch details, broader version range, or active exploitation evidence is provided. Avoid assuming affected versions beyond those cited.
Mitigation direction
- Check OpenBSD vendor guidance for fixed versions or official remediation.
- Inventory OpenBSD 6.9 systems and prioritize them for review.
- Reduce low-privileged local access where it is not operationally required.
- Monitor vendor and scanner updates for CVE-2021-34999 coverage.
Validation and detection
- Confirm whether any assets run OpenBSD 6.9.
- Identify systems allowing untrusted or semi-trusted local code execution.
- Review vulnerability management tools for CVE-2021-34999 detection status.
- Verify remediation against OpenBSD guidance once an official fix path is confirmed.
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-2021-34999 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
- 3.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/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:C/C:L/I:N/A:N21.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
3.8LowVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- ZDI-22-073CVE 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.