Security readout for executives and security teams
Plain-English summary
This is a Linux kernel memory-safety bug in the rtl8192e staging wireless driver. During PCI device disconnect, the code freed a network device pointer and then used it again. Business urgency depends on whether systems actually load this Realtek rtl8192e driver; the source bundle gives no CVSS score or confirmed exploitation.
Executive priority
Treat as targeted hygiene rather than an emergency unless affected hardware and driver use are confirmed. No active exploitation is cited, but kernel memory-safety defects should be remediated through normal kernel update cycles.
Technical view
CVE-2021-47571 fixes a use-after-free in _rtl92e_pci_disconnect(). The kernel commit message says free_rtllib() frees the dev pointer, and the next line used that freed pointer. Stable kernel commits rearranged the disconnect cleanup order to avoid the dangling access.
Likely exposure
Exposure is most plausible on Linux systems using the rtl8192e staging driver for affected Realtek wireless hardware. Servers, cloud workloads, and systems without this driver loaded are less likely to be exposed, but package backports must be checked.
Exploitation context
The bundle marks KEV as false and provides no public exploit evidence. The vulnerable path is a PCI disconnect cleanup path, so practical risk depends on local hardware, driver loading, and whether an attacker can influence device removal or driver teardown conditions.
Researcher notes
Evidence is limited to the CVE record and Linux stable commits. There is no CVSS, CWE, CPE, exploit status, or detailed impact statement in the bundle. Avoid assuming privilege escalation or remote reachability without additional vendor evidence.
Mitigation direction
- Identify systems running Linux kernels with rtl8192e support enabled or loaded.
- Update to a vendor kernel containing the referenced stable fixes.
- Check distribution advisories for backported fixes before relying on upstream version numbers.
- Remove or blacklist rtl8192e where unsupported hardware is not needed.
- Prioritize endpoints or appliances with Realtek rtl8192e wireless devices.
Validation and detection
- Inventory kernel versions and distribution package changelogs for CVE-2021-47571.
- Check whether the rtl8192e module is present, enabled, or loaded.
- Confirm vendor kernel source includes one of the referenced stable commits or equivalent patch.
- Review asset classes where PCI wireless device disconnect events are plausible.
- Track remediation evidence separately for vendor-backported kernels.
Public sources used
- CVE Program
- CVE List V5
- Linux stable commit d43aecb694b10db9a4228ce2d38b5ae8de374443
- Linux stable commit 9186680382934b0e7529d3d70dcc0a21d087683b
- Linux stable commit c0ef0e75a858cbd8618b473f22fbca36106dcf82
- Linux stable commit bca19bb2dc2d89ce60c4a4a6e59609d4cf2e13ef
- Linux stable commit 2e1ec01af2c7139c6a600bbfaea1a018b35094b6
- Linux stable commit 8d0163cec7de995f9eb9c3128c83fb84f0cb1c64
- Linux stable commit e27ee2f607fe6a9b923ef1fc65461c0613c97594
- Linux stable commit b535917c51acc97fb0761b1edec85f1f3d02bda4
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-2021-47571 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/d43aecb694b10db9a4228ce2d38b5ae8de374443CVE reference, Linux
- https://git.kernel.org/stable/c/9186680382934b0e7529d3d70dcc0a21d087683bCVE reference, Linux
- https://git.kernel.org/stable/c/c0ef0e75a858cbd8618b473f22fbca36106dcf82CVE reference, Linux
- https://git.kernel.org/stable/c/bca19bb2dc2d89ce60c4a4a6e59609d4cf2e13efCVE reference, Linux
- https://git.kernel.org/stable/c/2e1ec01af2c7139c6a600bbfaea1a018b35094b6CVE reference, Linux
- https://git.kernel.org/stable/c/8d0163cec7de995f9eb9c3128c83fb84f0cb1c64CVE reference, Linux
- https://git.kernel.org/stable/c/e27ee2f607fe6a9b923ef1fc65461c0613c97594CVE reference, Linux
- https://git.kernel.org/stable/c/b535917c51acc97fb0761b1edec85f1f3d02bda4CVE 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.