What is CVE-2021-47191?

CVE-2021-47191 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10, classified as a Out-of-bounds Read flaw (CWE-125). CVE-2021-47191 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47191?

CVE-2021-47191 has a CVSS score of 7.1 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Is there a patch available for CVE-2021-47191?

No patch is currently available for CVE-2021-47191. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-47191 actively exploited?

CVE-2021-47191 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/125.html

CVE-2021-47191

High

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Fix out-of-bound read in resp_readcap16() The following warning was observed running syzkaller: [ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in; [ 3813.830724] program syz-executor not setting count and/or reply_len properly [ 3813.836956] ================================================================== [ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549 [ 3813.846612] Call Trace: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] fill_from_dev_buffer+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] scsi_debug_queuecommand+0xb32/0x17e0 [ 3813.862699] scsi_dispatch_cmd+0x330/0x950 [ 3813.863329] scsi_request_fn+0xd8e/0x1710 [ 3813.863946] __blk_run_queue+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9 This issue can be reproduced with the following syzkaller log: r0 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='fd/3\x00') open_by_handle_at(r1, &(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x40782) write$binfmt_aout(r2, &(0x7f0000000340)=ANY=[@ANYBLOB="00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d"], 0x126) In resp_readcap16() we get "int alloc_len" value -1104926854, and then pass the huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This leads to OOB in sg_copy_buffer(). To solve this issue, define alloc_len as u32.

Package Linux Kernel

Published 2024-04-10

Last modified 2025-01-14

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

7.1

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness type

CWE-125

CVE-2021-47191 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2021-47191 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/3e20cb072679bdb47747ccc8bee3233a4cf0765a
Patch
Kernel patch commit
https://git.kernel.org/stable/c/4e3ace0051e7e504b55d239daab8789dd89b863c
Patch
Kernel patch commit
https://git.kernel.org/stable/c/5b8bed6464ad6653586e30df046185fd816ad999
Patch

Details

CVE ID CVE-2021-47191

Severity High

CVSS score 7.1 / 10

CVSS version 3.1

Published 2024-04-10

Modified 2025-01-14

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-47191?

CVE-2021-47191 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . CVE-2021-47191 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47191?

CVE-2021-47191 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.
Is there a patch available for CVE-2021-47191?

No patch is currently available for CVE-2021-47191. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-47191 actively exploited?

No — CVE-2021-47191 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →