CVE-2021-47633

What it is

In the Linux kernel, the following vulnerability has been resolved: ath5k: fix OOB in ath5k_eeprom_read_pcal_info_5111 The bug was found during fuzzing. Stacktrace locates it in ath5k_eeprom_convert_pcal_info_5111. When none of the curve is selected in the loop, idx can go up to AR5K_EEPROM_N_PD_CURVES. The line makes pd out of bound. pd = &chinfo[pier].pd_curves[idx]; There are many OOB writes using pd later in the code. So I added a sanity check for idx. Checks for other loops involving AR5K_EEPROM_N_PD_CURVES are not needed as the loop index is not used outside the loops. The patch is NOT tested with real device. The following is the fuzzing report BUG: KASAN: slab-out-of-bounds in ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] Write of size 1 at addr ffff8880174a4d60 by task modprobe/214 CPU: 0 PID: 214 Comm: modprobe Not tainted 5.6.0 #1 Call Trace: dump_stack+0x76/0xa0 print_address_description.constprop.0+0x16/0x200 ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] __kasan_report.cold+0x37/0x7c ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] kasan_report+0xe/0x20 ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] ? apic_timer_interrupt+0xa/0x20 ? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k] ? ath5k_pci_eeprom_read+0x228/0x3c0 [ath5k] ath5k_eeprom_init+0x2513/0x6290 [ath5k] ? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k] ? usleep_range+0xb8/0x100 ? apic_timer_interrupt+0xa/0x20 ? ath5k_eeprom_read_pcal_info_2413+0x2f20/0x2f20 [ath5k] ath5k_hw_init+0xb60/0x1970 [ath5k] ath5k_init_ah+0x6fe/0x2530 [ath5k] ? kasprintf+0xa6/0xe0 ? ath5k_stop+0x140/0x140 [ath5k] ? _dev_notice+0xf6/0xf6 ? apic_timer_interrupt+0xa/0x20 ath5k_pci_probe.cold+0x29a/0x3d6 [ath5k] ? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k] ? mutex_lock+0x89/0xd0 ? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k] local_pci_probe+0xd3/0x160 pci_device_probe+0x23f/0x3e0 ? pci_device_remove+0x280/0x280 ? pci_device_remove+0x280/0x280 really_probe+0x209/0x5d0

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-02-26 06:37 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 7.1 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-02-26 06:37 UTC

Last modified

2026-06-17 04:18 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-125 · Out-of-bounds read

Record status

Analyzed

Affected

• Linux Kernel < 4.9.311
• Linux Kernel < 4.14.276
• Linux Kernel < 4.19.238
• Linux Kernel < 5.4.189
• Linux Kernel < 5.10.111
• Linux Kernel < 5.15.34
• Linux Kernel < 5.16.20
• Linux Kernel < 5.17.3

Attack profile CVSS 3.1 · 7.1

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-47633.md and follow it. Check whether this project is affected by CVE-2021-47633. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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