CVE-2021-47434: xhci: Fix command ring pointer corruption while aborting a command
Vulnerability summary
CVE-2021-47434 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14.7% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 11 · Related 11Timeline
- 22-05-2024PublishedVulnerability first disclosed.
- 23-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: xhci: Fix command ring pointer corruption while aborting a command The command ring pointer is located at [6:63] bits of the command ring control register (CRCR). All the control bits like command stop, abort are located at [0:3] bits. While aborting a command, we read the CRCR and set the abort bit and write to the CRCR. The read will always give command ring pointer as all zeros. So we essentially write only the control bits. Since we split the 64 bit write into two 32 bit writes, there is a possibility of xHC command ring stopped before the upper dword (all zeros) is written. If that happens, xHC updates the upper dword of its internal command ring pointer with all zeros. Next time, when the command ring is restarted, we see xHC memory access failures. Fix this issue by only writing to the lower dword of CRCR where all control bits are located.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.24%
Chance of exploitation in the next 30 days
Percentile
15%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.24% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu88 products
- linuxAll versions (No fix recorded) | < 4.15.0-166.174 | < 5.4.0-92.103
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 4.15.0-1118.125 | < 5.4.0-1061.64
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ b92cc66c047ff7cf587b318fe377061a353c120f, < 22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 | ≥ b92cc66c047ff7cf587b318fe377061a353c120f, < 62c182b5e763e5f4062e72678e72ce3e02dd4d1b | ≥ b92cc66c047ff7cf587b318fe377061a353c120f, < 01c2dcb67e71c351006dd17cbba86c26b7f61eaf | ≥ b92cc66c047ff7cf587b318fe377061a353c120f, < dec944bb7079b37968cf69c8a438f91f15c4cc61 | ≥ b92cc66c047ff7cf587b318fe377061a353c120f, < e54abefe703ab7c4e5983e889babd1447738ca42 | ≥ b92cc66c047ff7cf587b318fe377061a353c120f, < ff0e50d3564f33b7f4b35cadeabd951d66cfc570 | bc47204b268516ae4085ebdc81a34ddda71b77c4 | 88bd928daafb5912c269af628b1e5347620c9a62 | 2818247b6565b7adfbcd53b74509448a8e1fad84 | ef6273930e170a4f70a2c7f57a214813c5cf30bb | f83994f3e2438b982fb9821d948199b3327638d8 | ≥ 3.0.49, < 3.1 | ≥ 3.2.32, < 3.3 | ≥ 3.4.13, < 3.5 | ≥ 3.5.6, < 3.6 | ≥ 3.6.1, < 3.7 | 3.7
- linux_kernel< 4.14.252 | ≥ 4.15, < 4.19.213 | ≥ 4.20, < 5.4.155 | ≥ 5.5, < 5.10.75 | ≥ 5.11, < 5.14.14 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3 | 5.15:rc4 | 5.15:rc5
Debian1 product
- linux< 5.14.16-1
3 vendors · 91 products
