Security readout for executives and security teams
Plain-English summary
CVE-2021-47449 is a Linux kernel driver flaw in the ice network driver’s transmit timestamp cleanup path. During device removal, incorrect locking can let a sleepable firmware mutex run in an invalid context, risking deadlock and service disruption on affected systems.
Executive priority
Treat this as high priority for Linux infrastructure using affected network drivers, especially servers where network availability matters. It is not currently supported as actively exploited, but kernel networking deadlocks can create operational outages.
Technical view
The vulnerable path holds a lock around Tx timestamp tracker flush while calling ice_clear_phy_tstamp, which takes a mutex to issue a PHY write command to firmware. The source shows kernel preemption debugging warning during rmmod/device removal. CVSS is 7.1 with local, low-complexity, low-privilege impact to integrity and availability.
Likely exposure
Exposure is mainly Linux systems using affected kernel builds with the ice driver and relevant hardware/driver paths. The bundle lists Linux kernel commits and version 5.14.4, but downstream distribution package status is not provided.
Exploitation context
The CVE is not listed as KEV, and the provided sources do not report active exploitation. The described trigger context is local device removal or module unload behavior causing a locking fault, not a remote network attack.
Researcher notes
The source data describes a locking/deadlock defect, while the listed CWE-129 appears mismatched or at least insufficiently explanatory. Affected-version evidence is incomplete for downstream kernels, so validation should focus on vendor backports and exact package provenance.
Mitigation direction
- Apply Linux kernel updates containing the referenced stable fixes.
- Check your Linux distribution or appliance vendor advisory for backported fixes.
- Prioritize hosts using the ice driver in production networking paths.
- Plan maintenance windows for kernel update and reboot where required.
- Avoid treating source commit hashes as complete downstream package coverage.
Validation and detection
- Inventory Linux hosts using the ice driver and affected kernel builds.
- Verify installed kernel changelogs include the referenced stable fix commits.
- Review kernel logs for sleeping-in-invalid-context warnings involving ice_clear_phy_tstamp.
- Confirm distribution security trackers mark the deployed package as fixed.
- Test driver removal or maintenance workflows only in controlled non-production environments.
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-129: 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 lookupCVE-2021-47449 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:N/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.
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:N/I:H/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:N/I:H/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/61616be899975404df44c20ab902464b60882cd7CVE reference, Linux
- https://git.kernel.org/stable/c/4d4a223a86afe658cd878800f09458e8bb54415dCVE 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.
Improper Validation of Array Index
Improper Validation of Array Index represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.