Security readout for executives and security teams
Plain-English summary
This Linux kernel issue affects the older mISDN ISDN driver path. A release function could run where sleeping is not allowed, triggering a kernel BUG report during driver removal or unload. Business impact is likely limited unless affected ISDN hardware or modules are used.
Executive priority
Treat this as a targeted kernel hygiene item, not an emergency, unless the organization uses ISDN hardware or loads these modules. Prioritize confirmation and patch alignment through normal kernel maintenance.
Technical view
The mISDN netjet path can call card->isac.release() while in atomic context with interrupts disabled. The kernel fix moves that release call until after the lock is released. The supplied record does not provide CVSS, CWE, or a confirmed security impact beyond the invalid-context BUG trace.
Likely exposure
Exposure appears limited to Linux systems running affected kernel versions with mISDN ISDN support, particularly the netjet driver path. Cloud, container, and standard server fleets are less likely exposed unless those modules are present or loadable.
Exploitation context
The bundle does not show CISA KEV listing or any cited active exploitation. The visible trigger context is local driver removal or module handling, not a remote network attack path. Exploitability and impact remain under-specified in the supplied sources.
Researcher notes
The record identifies a locking-context bug, but not a clear attacker model, privilege requirement, or final impact. Research should focus on affected module reachability, whether unprivileged users can trigger load or removal paths, and vendor backport status.
Mitigation direction
- Update to a vendor-supported kernel containing the referenced stable mISDN fix.
- Confirm distribution kernel advisories because vendors may backport fixes without changing upstream version numbers.
- Disable or avoid loading unused mISDN and netjet modules where operationally safe.
- Prioritize remediation on systems with ISDN hardware or kernel module management exposure.
Validation and detection
- Inventory kernels and check whether mISDN or netjet modules are installed or loaded.
- Map installed kernel packages to vendor advisories for CVE-2021-47468.
- Review kernel logs for invalid-context BUG traces involving mISDN, netjet, or isac_release.
- Confirm updated kernels include one of the referenced upstream stable fixes or vendor backports.
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.
CVE-2021-47468 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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
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/6f95c97e0f9d6eb39c3f2cb45e8fa4268d1b372bCVE reference, Linux
- https://git.kernel.org/stable/c/ef269a8808cb1759245a98a7fe16fceaebad894cCVE reference, Linux
- https://git.kernel.org/stable/c/37e4f57b22cc5ebb3f80cf0f74fdeb487f082367CVE reference, Linux
- https://git.kernel.org/stable/c/a5b34409d3fc52114c828be4adbc30744fa3258bCVE reference, Linux
- https://git.kernel.org/stable/c/4054b869dc263228d30a4755800b78f0f2ba0c89CVE reference, Linux
- https://git.kernel.org/stable/c/9f591cbdbed3d7822b2bdba89b34a6d7b434317dCVE reference, Linux
- https://git.kernel.org/stable/c/f5966ba53013149bcf94e1536644a958dd00a026CVE reference, Linux
- https://git.kernel.org/stable/c/6510e80a0b81b5d814e3aea6297ba42f5e76f73cCVE 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.