Out-of-Bounds Read in Linux kernel (CVE-2021-47219)
Summary
Vulnerability in Linux kernel (CVE-2021-47219). Confidential information can be exposed externally.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
scsi: scsi_debug: Fix out-of-bound read in resp_report_tgtpgs()
The following issue was observed running syzkaller:
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:377 [inline]
BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831
Read of size 2132 at addr ffff8880aea95dc8 by task syz-executor.0/9815
CPU: 0 PID: 9815 Comm: syz-executor.0 Not tainted 4.19.202-00874-gfc0fe04215a9 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xe4/0x14a lib/dump_stack.c:118
print_address_description+0x73/0x280 mm/kasan/report.c:253
kasan_report_error mm/kasan/report.c:352 [inline]
kasan_report+0x272/0x370 mm/kasan/report.c:410
memcpy+0x1f/0x50 mm/kasan/kasan.c:302
memcpy include/linux/string.h:377 [inline]
sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831
fill_from_dev_buffer+0x14f/0x340 drivers/scsi/scsi_debug.c:1021
resp_report_tgtpgs+0x5aa/0x770 drivers/scsi/scsi_debug.c:1772
schedule_resp+0x464/0x12f0 drivers/scsi/scsi_debug.c:4429
scsi_debug_queuecommand+0x467/0x1390 drivers/scsi/scsi_debug.c:5835
scsi_dispatch_cmd+0x3fc/0x9b0 drivers/scsi/scsi_lib.c:1896
scsi_request_fn+0x1042/0x1810 drivers/scsi/scsi_lib.c:2034
__blk_run_queue_uncond block/blk-core.c:464 [inline]
__blk_run_queue+0x1a4/0x380 block/blk-core.c:484
blk_execute_rq_nowait+0x1c2/0x2d0 block/…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-47219 has been found in Linux kernel.
Confidential information can be exposed externally. CVSS score: 7.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2021-47219" on the vendor's site.
CVE-2021-47219 (Linux kernel) — CWE-125 / CVSS v3 7.1
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds read (CWE-125) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2021-47219 linux Fixed in: 5.15.5-1
- Ubuntu UBUNTU-CVE-2021-47219 linux
References
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- web nvd.nist.gov
- web github.com