Linux: Improper Validation of Array Index
CVE-2022-49720 is a high-severity improper validation of array index vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 7fa28a7c3d74933a4fc22d341b60927952f31c19, b5e65ef044d627effdc2599040b6d204e003f955, b202a0bd2580ee5b0453772c46d464152fafff73 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 7fa28a7c3d74933a4fc22d341b60927952f31c19 or b5e65ef044d627effdc2599040b6d204e003f955 or b202a0bd2580ee5b0453772c46d464152fafff73 or 14dc7a18abbe4176f5626c13c333670da8e06aa1, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.214 or 5.15.49 or 5.18.6, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 20e4d813931961fe26d26a1e98b3aba6ec00b130 up to, but not including, 7fa28a7c3d74933a4fc22d341b60927952f31c19; 20e4d813931961fe26d26a1e98b3aba6ec00b130 up to, but not including, b5e65ef044d627effdc2599040b6d204e003f955; 20e4d813931961fe26d26a1e98b3aba6ec00b130 up to, but not including, b202a0bd2580ee5b0453772c46d464152fafff73; 20e4d813931961fe26d26a1e98b3aba6ec00b130 up to, but not including, 14dc7a18abbe4176f5626c13c333670da8e06aa1; 4.16 | 7fa28a7c3d74933a4fc22d341b60927952f31c19, b5e65ef044d627effdc2599040b6d204e003f955, b202a0bd2580ee5b0453772c46d464152fafff73, 14dc7a18abbe4176f5626c13c333670da8e06aa1 |
| Linux | Linux Kernel | 4.16 up to, but not including, 5.10.214; 5.11 up to, but not including, 5.15.49; 5.16 up to, but not including, 5.18.6; 5.19 | 5.10.214, 5.15.49, 5.18.6 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: block: Fix handling of offline queues in blk_mq_alloc_request_hctx() This patch prevents that test nvme/004 triggers the following: UBSAN: array-index-out-of-bounds in block/blk-mq.h:135:9 index 512 is out of range for type 'long unsigned int [512]' Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 ubsan_epilogue+0x9/0x3b __ubsan_handle_out_of_bounds.cold+0x44/0x49 blk_mq_alloc_request_hctx+0x304/0x310 __nvme_submit_sync_cmd+0x70/0x200 [nvme_core] nvmf_connect_io_queue+0x23e/0x2a0 [nvme_fabrics] nvme_loop_connect_io_queues+0x8d/0xb0 [nvme_loop] nvme_loop_create_ctrl+0x58e/0x7d0 [nvme_loop] nvmf_create_ctrl+0x1d7/0x4d0 [nvme_fabrics] nvmf_dev_write+0xae/0x111 [nvme_fabrics] vfs_write+0x144/0x560 ksys_write+0xb7/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Validation of Array Index
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
How developers prevent this class of flaw
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
- Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.
More Improper Validation of Array Index vulnerabilities (CWE-129)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Improper Validation of Array Index vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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