Security readout for executives and security teams
Plain-English summary
CVE-2021-47219 is a Linux kernel bug in the scsi_debug driver. A large user-provided length could trigger an out-of-bounds read and kernel memory safety failure. The sources show a kernel fix, but no CVSS score and no evidence of active exploitation.
Executive priority
Treat this as a patch-management item unless scsi_debug is intentionally used in sensitive environments. The business urgency is reduced by unknown severity and no cited exploitation, but kernel memory safety bugs still warrant routine remediation.
Technical view
In resp_report_tgtpgs(), an int length value could become negative when userspace supplied a large length. That value flowed into buffer-copy handling, producing a KASAN slab out-of-bounds read. The kernel fix changes n, alen, and rlen to u32.
Likely exposure
Exposure appears limited to Linux systems where the scsi_debug driver is present and reachable. The source bundle does not prove broad default exposure, remote reachability, or impact beyond the reported out-of-bounds read path.
Exploitation context
The issue was found by syzkaller and reported with a KASAN crash trace. CISA KEV status is false, and the provided sources do not claim public exploitation or weaponized use.
Researcher notes
The strongest evidence is the kernel commit description and KASAN trace. Missing evidence includes CVSS, CWE, exact distribution package status, exploitability assessment, and whether confidentiality impact is practical outside the fuzzed crash path.
Mitigation direction
- Update to a vendor kernel containing the linked stable fixes.
- Backport the referenced commits if maintaining a custom kernel.
- Check distribution advisories for exact fixed package versions.
- Review whether scsi_debug is needed on production systems.
Validation and detection
- Inventory Linux kernels and map them against vendor fixed versions.
- Check whether the scsi_debug driver is available or loaded.
- Confirm patched source uses u32 for n, alen, and rlen.
- Run existing kernel or platform regression tests after update.
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
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CVE-2021-47219 mapping review
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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/8440377e1a5644779b4c8d013aa2a917f5fc83c3CVE reference, Linux
- https://git.kernel.org/stable/c/66523553fa62c7878fc5441dc4e82be71934eb77CVE reference, Linux
- https://git.kernel.org/stable/c/f347c26836c270199de1599c3cd466bb7747caa9CVE 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.