Security readout for executives and security teams
Plain-English summary
This is a Linux kernel flaw in the ipack ipoctal driver. A local user with some privileges could potentially trigger incorrect module reference handling, creating confidentiality and availability risk. The source bundle does not show internet exposure or active exploitation.
Executive priority
Treat as a high-priority kernel maintenance issue for affected Linux fleets, especially shared or privileged-access environments. It is less urgent than remotely exploitable KEV-listed bugs, but kernel confidentiality and availability impact justifies timely patch validation.
Technical view
The ipoctal tty path took a carrier module reference on every open but released it only when the final tty structure reference was dropped. The kernel fix moves reference taking and driver data initialization to tty installation. CVSS marks local, low-complexity, low-privilege exploitation with high confidentiality and availability impact.
Likely exposure
Exposure is most likely on Linux systems running affected kernel versions where the ipack ipoctal driver is present or usable. The bundle lists affected Linux versions from 3.18 through 5.15-related stable lines, but does not define distribution package status.
Exploitation context
CISA KEV status is false in the bundle, and no cited source reports active exploitation. The CVSS vector requires local access and low privileges, so this is not described as a remote network attack.
Researcher notes
Evidence is limited to the CVE record and upstream stable commit references. The affected-version list appears kernel-oriented rather than distribution-specific. Do not assume exploit availability, remote reachability, or product impact beyond Linux kernel ipoctal handling without vendor confirmation.
Mitigation direction
- Update affected Linux kernels to vendor-supported builds containing the referenced stable fixes.
- Check Linux distribution advisories for backported patches and exact package versions.
- Prioritize multi-user systems and systems exposing the ipoctal driver to local users.
- If patch timing is delayed, follow vendor guidance for reducing driver exposure.
Validation and detection
- Inventory kernel versions and compare them with distribution security advisories for CVE-2021-47403.
- Confirm whether the ipoctal driver is built, available, or loaded on relevant systems.
- Verify patched kernels include the stable commits referenced by the CVE record.
- Document any compensating controls if affected systems cannot be patched promptly.
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-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. 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 lookupCVE-2021-47403 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
- High
- CVSS
- 7.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.
SSVC decision data
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H1.85.2CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.1HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/31398849b84ebae0d43a1cf379cb9895597f221aCVE reference, Linux
- https://git.kernel.org/stable/c/c0adb5a947dec6cff7050ec56d78ecd3916f9ce6CVE reference, Linux
- https://git.kernel.org/stable/c/dde4c1429b97383689f755ce92b4ed1e84a9c92bCVE reference, Linux
- https://git.kernel.org/stable/c/9c5b77a7ffc983b2429ce158b50497c5d3c86a69CVE reference, Linux
- https://git.kernel.org/stable/c/3253c87e1e5bc0107aab773af2f135ebccf38666CVE reference, Linux
- https://git.kernel.org/stable/c/7cea848678470daadbfdaa6a112b823c290f900cCVE reference, Linux
- https://git.kernel.org/stable/c/811178f296b16af30264def74c8d2179a72d5562CVE reference, Linux
- https://git.kernel.org/stable/c/bb8a4fcb2136508224c596a7e665bdba1d7c3c27CVE reference, Linux
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.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.