Security readout for executives and security teams
Plain-English summary
CVE-2021-47525 is a Linux kernel issue in the LiteUART serial driver. When the driver is unbound, the serial port may remain registered after driver data is released, creating use-after-free risk and a memory leak. Business impact depends on whether systems use this uncommon LiteUART driver.
Executive priority
Handle through normal kernel maintenance unless LiteUART is used in critical embedded systems. Prioritize embedded Linux assets and custom kernels because downstream patch status is not established by the provided sources.
Technical view
The flaw is in Linux kernel serial/liteuart unbind handling. The fix deregisters the port during driver removal so serial core cannot use freed driver data and does not leak allocated memory. Sources do not provide CVSS, CWE, exploitability details, or a broad affected distribution matrix.
Likely exposure
Exposure appears limited to Linux systems with affected kernels and the LiteUART serial driver present or enabled. The provided CVE data lists Linux kernel versions and stable kernel commits, but does not identify specific downstream distributions or appliances.
Exploitation context
The source bundle does not show active exploitation, public exploit activity, or CISA KEV listing. Practical exploitation requirements are not described in the sources. Treat this as a kernel reliability and memory-safety issue requiring vendor-guided patch assessment.
Researcher notes
Key uncertainty is exploitability. The bug class is memory safety during driver unbind, but the sources do not describe attacker prerequisites, privilege requirements, crash impact, or post-free control. Analysis should focus on driver reachability and vendor patch provenance.
Mitigation direction
- Check Linux distribution or kernel vendor advisories for CVE-2021-47525.
- Upgrade to a kernel containing the referenced stable fixes.
- Disable or avoid LiteUART driver use where it is not operationally required.
- Track affected embedded or FPGA-based Linux builds separately from general servers.
Validation and detection
- Inventory Linux kernels and identify systems with LiteUART support enabled.
- Check kernel package changelogs for the referenced stable commits.
- Confirm whether LiteUART hardware or driver modules are used in production.
- Review vendor advisories for affected version ranges and fixed package names.
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-2021-47525 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/602824cf9aa9db8830ffe5cfb2cd54365cada4feCVE reference, Linux
- https://git.kernel.org/stable/c/05f929b395dec8957b636ff14e66b277ed022ed9CVE 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.