CVE-2021-47211: ALSA: usb-audio: fix null pointer dereference on pointer cs_desc
Vulnerability summary
CVE-2021-47211 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15.2% 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 25 · Related 25Timeline
- 10-04-2024PublishedVulnerability first disclosed.
- 19-06-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix null pointer dereference on pointer cs_desc The pointer cs_desc return from snd_usb_find_clock_source could be null, so there is a potential null pointer dereference issue. Fix this by adding a null check before dereference.
CVSS metrics
4 scores · 3 sources · 2 versions- 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 causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu90 products
- linuxAll versions (No fix recorded) | < 4.4.0-269.303 | < 4.15.0-238.250 | < 5.4.0-218.238
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.4.0-1144.150 | < 4.4.0-1182.197 | < 4.15.0-1181.194 | < 5.4.0-1147.157
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 1dc669fed61a4ec4270a89e5fb3535802cc45668, < 3455984b16eeb6914caf8b59498ef24fcc1f0a78 | ≥ 1dc669fed61a4ec4270a89e5fb3535802cc45668, < 58fa50de595f152900594c28ec9915c169643739 | ≥ 1dc669fed61a4ec4270a89e5fb3535802cc45668, < b97053df0f04747c3c1e021ecbe99db675342954 | 3.10
- linux_kernel< 5.15.5
Debian1 product
- linux< 5.15.5-1
3 vendors · 93 products
