Linux: Improper Validation of Array Index
CVE-2022-49471 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 03ed236480aeec8c2fd327a1ea6d711364c495e3, c32fafe68298bb599e825c298e1d0ba30186f0a5, 97df85871a5b187609d30fca6d85b912d9e02f29 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 0.32% 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 03ed236480aeec8c2fd327a1ea6d711364c495e3 or c32fafe68298bb599e825c298e1d0ba30186f0a5 or 97df85871a5b187609d30fca6d85b912d9e02f29, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.17.14 or 5.18.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | e3ec7017f6a20d12ddd9fe23d345ebb7b8c104dd up to, but not including, 03ed236480aeec8c2fd327a1ea6d711364c495e3; e3ec7017f6a20d12ddd9fe23d345ebb7b8c104dd up to, but not including, c32fafe68298bb599e825c298e1d0ba30186f0a5; e3ec7017f6a20d12ddd9fe23d345ebb7b8c104dd up to, but not including, 97df85871a5b187609d30fca6d85b912d9e02f29; 5.16 | 03ed236480aeec8c2fd327a1ea6d711364c495e3, c32fafe68298bb599e825c298e1d0ba30186f0a5, 97df85871a5b187609d30fca6d85b912d9e02f29 |
| Linux | Linux Kernel | before 5.17.14; 5.18 up to, but not including, 5.18.3 | 5.17.14, 5.18.3 |
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 | 8.8 | High | CNA |
| 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: rtw89: cfo: check mac_id to avoid out-of-bounds Somehow, hardware reports incorrect mac_id and pollute memory. Check index before we access the array. UBSAN: array-index-out-of-bounds in rtw89/phy.c:2517:23 index 188 is out of range for type 's32 [64]' CPU: 1 PID: 51550 Comm: irq/35-rtw89_pc Tainted: G OE Call Trace: <IRQ> show_stack+0x52/0x58 dump_stack_lvl+0x4c/0x63 dump_stack+0x10/0x12 ubsan_epilogue+0x9/0x45 __ubsan_handle_out_of_bounds.cold+0x44/0x49 ? __alloc_skb+0x92/0x1d0 rtw89_phy_cfo_parse+0x44/0x7f [rtw89_core] rtw89_core_rx+0x261/0x871 [rtw89_core] ? __alloc_skb+0xee/0x1d0 rtw89_pci_napi_poll+0x3fa/0x4ea [rtw89_pci] __napi_poll+0x33/0x1a0 net_rx_action+0x126/0x260 ? __queue_work+0x217/0x4c0 __do_softirq+0xd9/0x315 ? disable_irq_nosync+0x10/0x10 do_softirq.part.0+0x6d/0x90 </IRQ> <TASK> __local_bh_enable_ip+0x62/0x70 rtw89_pci_interrupt_threadfn+0x182/0x1a6 [rtw89_pci] irq_thread_fn+0x28/0x60 irq_thread+0xc8/0x190 ? irq_thread_fn+0x60/0x60 kthread+0x16b/0x190 ? irq_thread_check_affinity+0xe0/0xe0 ? set_kthread_struct+0x50/0x50 ret_from_fork+0x22/0x30 </TASK>
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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