CVE-2021-4149: debian debian_linux Improper Locking

Modified

AliasesUBUNTU-CVE-2021-4149DEBIAN-CVE-2021-4149

Published 23-03-2022Last modified 03-08-2024

Vulnerability summary

CVE-2021-4149 is a medium (CVSS 5.5) Improper Locking vulnerability in debian debian_linux. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 34.3% of scored vulnerabilities. 2 public exploits are recorded.

Priority

Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

5.5/10

010

Medium · v3.1 (NVD)

EPSS score

0.40%

0%100%

Low · 0.00 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits2reference

Timeline

23-03-2022
PublishedVulnerability first disclosed.
03-08-2024
Last modifiedVulnerability information updated.

Description

A vulnerability was found in btrfs_alloc_tree_b in fs/btrfs/extent-tree.c in the Linux kernel due to an improper lock operation in btrfs. In this flaw, a user with a local privilege may cause a denial of service (DOS) due to a deadlock problem.

CVSS metrics

5 scores · 3 sources · 3 versions

v4.05.7v3.15.5v2.02.1

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

34%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.40% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs

CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

2 found

referenceUnverified
Exploit Reference (lkml.org)
Maturity: unknown
referenceUnverified
Exploit Reference (lkml.org)
Maturity: unknown

Weaknesses

CWE · root cause

CWE-667Improper LockingThe product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu63 products

linux< 4.4.0-239.273 | < 4.15.0-184.194 | < 5.4.0-92.103
linux-aws< 4.4.0-1117.123 | < 4.4.0-1155.170 | < 4.15.0-1133.143 | < 5.4.0-1061.64
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.11< 5.11.0-1023.24~20.04.1
linux-aws-5.3All versions (No fix recorded)

linux-aws-5.4< 5.4.0-1061.64~18.04.1
linux-aws-5.8All versions (No fix recorded)
linux-aws-fips< 4.15.0-2072.76 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1133.143~16.04.1
linux-azure< 4.15.0-1142.156~14.04.1 | < 4.15.0-1142.156~16.04.1 | All versions (No fix recorded) | < 5.4.0-1065.68
linux-azure-4.15< 4.15.0-1142.156
linux-azure-5.11< 5.11.0-1023.24~20.04.1
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1065.68~18.04.1
linux-azure-5.8All versions (No fix recorded)
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fips< 4.15.0-2053.58 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-bluefield< 5.4.0-1023.26
linux-dell300x< 4.15.0-1047.52
linux-fips< 4.4.0-1088.95 | All versions (No fix recorded) | < 4.15.0-1090.100 | < 5.4.0-1038.44
linux-gcp< 4.15.0-1127.142~16.04.1 | All versions (No fix recorded) | < 5.4.0-1059.63
linux-gcp-4.15< 4.15.0-1127.142
linux-gcp-5.11< 5.11.0-1024.26~20.04.1
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1059.63~18.04.1
linux-gcp-5.8All versions (No fix recorded)
linux-gcp-fips< 4.15.0-2037.41 | All versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1057.60
linux-gke-4.15All versions (No fix recorded)
linux-gke-5.4< 5.4.0-1057.60~18.04.1
linux-gkeop< 5.4.0-1029.30
linux-gkeop-5.4< 5.4.0-1029.30~18.04.2
linux-hwe< 4.15.0-184.194~16.04.1 | All versions (No fix recorded)
linux-hwe-5.11All versions (No fix recorded)
linux-hwe-5.13< 5.13.0-23.23~20.04.2
linux-hwe-5.4< 5.4.0-92.103~18.04.2
linux-hwe-5.8All versions (No fix recorded)
linux-hwe-edgeAll versions (No fix recorded)
linux-ibm< 5.4.0-1010.11
linux-intel-5.13All versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvm< 4.4.0-1118.128 | < 4.15.0-1119.123 | < 5.4.0-1051.53
linux-lts-xenial< 4.4.0-239.273~14.04.1
linux-oemAll versions (No fix recorded)
linux-oem-5.10< 5.10.0-1051.53
linux-oem-5.13< 5.13.0-1026.32
linux-oem-5.14< 5.14.0-1007.7
linux-oem-5.6All versions (No fix recorded)
linux-oracle< 4.15.0-1098.108~16.04.1 | < 4.15.0-1098.108 | < 5.4.0-1059.63
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.11< 5.11.0-1023.24~20.04.1
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1059.63~18.04.1
linux-oracle-5.8All versions (No fix recorded)
linux-raspi< 5.4.0-1048.53
linux-raspi-5.4< 5.4.0-1048.53~18.04.1
linux-raspi-realtimeAll versions (No fix recorded)
linux-raspi2< 4.15.0-1114.122 | All versions (No fix recorded)
linux-realtimeAll versions (No fix recorded)
linux-riscvAll versions (No fix recorded)
linux-riscv-5.11< 5.11.0-1024.25~20.04.1
linux-riscv-5.8All versions (No fix recorded)
linux-snapdragon< 4.15.0-1132.142

Show all 63

Debian2 products

linux< 5.14.16-1
debian_linuxEOL9.0

Linux1 product

linux_kernel< 5.15 | 5.15 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3 | 5.15:rc4 | 5.15:rc5

3 vendors · 66 products

References

13 links

bugzilla.redhat.com/show_bug.cgi?id=2026485X Refsource MISCIssue TrackingThird Party Advisory
lkml.org/lkml/2021/10/18/885X Refsource MISCExploitMailing ListPatchThird Party Advisory
lkml.org/lkml/2021/9/13/2565X Refsource MISCExploitMailing ListThird Party Advisory
lists.debian.org/debian-lts-announce/2022/07/msg00000.htmlMailing ListX Refsource MLISTThird Party Advisory
ubuntu.com/security/CVE-2021-4149REPORT
git.kernel.org/linus/19ea40dddf1833db868533958ca066f368862211REPORT
ubuntu.com/security/notices/USN-5466-1Advisory
ubuntu.com/security/notices/USN-6001-1Advisory
ubuntu.com/security/notices/USN-6013-1Advisory
ubuntu.com/security/notices/USN-6014-1Advisory

Show all 13 references

www.cve.org/CVERecord?id=CVE-2021-4149REPORT
security-tracker.debian.org/tracker/CVE-2021-4149Advisory
nvd.nist.gov/vuln/detail/CVE-2021-4149OvalAdvisory