CVE-2021-47207: ALSA: gus: fix null pointer dereference on pointer block
Vulnerability summary
CVE-2021-47207 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.3% 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
- 10-04-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: gus: fix null pointer dereference on pointer block The pointer block return from snd_gf1_dma_next_block 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
0.23%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.23% 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.
Ubuntu89 products
- linuxAll versions (No fix recorded) | < 4.15.0-167.175 | < 5.4.0-97.110
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 4.15.0-1119.127 | < 5.4.0-1064.67
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 3e28e083dcdf03a18a083f8a47b6bb6b1604b5be | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < cb09c760c201f82df83babc92a5ffea0a01807fc | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 542fa721594a02d2aee0370a764d306ef48d030c | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < ab4c1ebc40f699f48346f634d7b72b9c5193f315 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < c6d2cefdd05c4810c416fb8d384b5c377bd977bc | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 1ac6cd87d8ddd36c43620f82c4d65b058f725f0f | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 16721797dcef2c7c030ffe73a07f39a65f9323c3 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < a0d21bb3279476c777434c40d969ea88ca64f9aa | 2.6.12
- linux_kernel< 4.4.293 | ≥ 4.5, < 4.9.291 | ≥ 4.10, < 4.14.256 | ≥ 4.15, < 4.19.218 | ≥ 4.20, < 5.4.162 | ≥ 5.5, < 5.10.82 | ≥ 5.11, < 5.15.5
Debian1 product
- linux< 5.15.5-1
3 vendors · 92 products
