CVE-2021-20321: debian debian_linux

Modified

AliasesRHSA-2021:5227RHSA-2021:5241UBUNTU-CVE-2021-20321+1 more

Published 18-02-2022Last modified 03-08-2024

Vulnerability summary

CVE-2021-20321 is a medium (CVSS 4.7) vulnerability in debian debian_linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12% of scored vulnerabilities.

Priority

Routine

Not severe (CVSS 4.7, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

4.7/10

010

Medium · v3.1 (NVD)

EPSS score

0.22%

0%100%

Low · 0.00 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Timeline

18-02-2022
PublishedVulnerability first disclosed.
03-08-2024
Last modifiedVulnerability information updated.

Description

A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.

CVSS metrics

6 scores · 4 sources · 3 versions

v4.05.8v3.14.7v2.04.7

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.22% 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

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-362Concurrent Execution using Shared Resource with Improper SynchronizationThe product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

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

linuxAll versions (No fix recorded) | < 4.4.0-242.276 | < 4.15.0-166.174 | < 5.4.0-92.103
linux-aws< 4.4.0-1120.126 | < 4.4.0-1158.173 | < 4.15.0-1118.125 | < 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< 4.15.0-2059.61 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1118.125~16.04.1
linux-azure< 4.15.0-1129.142~14.04.1 | < 4.15.0-1129.142~16.04.1 | All versions (No fix recorded) | < 5.4.0-1065.68
linux-azure-4.15< 4.15.0-1129.142
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< 4.15.0-2041.45 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-bluefield< 5.4.0-1023.26
linux-dell300x< 4.15.0-1033.38
linux-fips< 4.4.0-1090.97 | All versions (No fix recorded) | < 4.15.0-1075.84 | < 5.4.0-1038.44
linux-gcp< 4.15.0-1114.128~16.04.1 | All versions (No fix recorded) | < 5.4.0-1059.63
linux-gcp-4.15< 4.15.0-1114.128
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< 4.15.0-2024.26 | 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< 4.15.0-166.174~16.04.1 | All versions (No fix recorded)
linux-hwe-5.11< 5.11.0-44.48~20.04.2
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< 4.4.0-1121.131 | < 4.15.0-1105.107 | < 5.4.0-1051.53
linux-lts-xenial< 4.4.0-242.276~14.04.1
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< 4.15.0-1085.93~16.04.1 | < 4.15.0-1085.93 | < 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< 4.15.0-1101.108 | 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< 4.15.0-1118.127

Show all 63

Redhat51 products

enterprise_linuxEOL7.0 | 8.0
bpftool< 0:4.18.0-348.7.1.el8_5
bpftool-debuginfo< 0:4.18.0-348.7.1.el8_5
kernel< 0:4.18.0-348.7.1.el8_5
kernel-abi-stablelists< 0:4.18.0-348.7.1.el8_5

kernel-core< 0:4.18.0-348.7.1.el8_5
kernel-cross-headers< 0:4.18.0-348.7.1.el8_5
kernel-debug< 0:4.18.0-348.7.1.el8_5
kernel-debug-core< 0:4.18.0-348.7.1.el8_5
kernel-debug-debuginfo< 0:4.18.0-348.7.1.el8_5
kernel-debug-devel< 0:4.18.0-348.7.1.el8_5
kernel-debug-modules< 0:4.18.0-348.7.1.el8_5
kernel-debug-modules-extra< 0:4.18.0-348.7.1.el8_5
kernel-debuginfo< 0:4.18.0-348.7.1.el8_5
kernel-debuginfo-common-aarch64< 0:4.18.0-348.7.1.el8_5
kernel-debuginfo-common-ppc64le< 0:4.18.0-348.7.1.el8_5
kernel-debuginfo-common-s390x< 0:4.18.0-348.7.1.el8_5
kernel-debuginfo-common-x86_64< 0:4.18.0-348.7.1.el8_5
kernel-devel< 0:4.18.0-348.7.1.el8_5
kernel-doc< 0:4.18.0-348.7.1.el8_5
kernel-modules< 0:4.18.0-348.7.1.el8_5
kernel-modules-extra< 0:4.18.0-348.7.1.el8_5
kernel-rt< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-core< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug-core< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug-debuginfo< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug-devel< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug-kvm< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug-modules< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debug-modules-extra< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debuginfo< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-debuginfo-common-x86_64< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-devel< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-kvm< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-modules< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-rt-modules-extra< 0:4.18.0-348.7.1.rt7.137.el8_5
kernel-tools< 0:4.18.0-348.7.1.el8_5
kernel-tools-debuginfo< 0:4.18.0-348.7.1.el8_5
kernel-tools-libs< 0:4.18.0-348.7.1.el8_5
kernel-tools-libs-devel< 0:4.18.0-348.7.1.el8_5
kernel-zfcpdump< 0:4.18.0-348.7.1.el8_5
kernel-zfcpdump-core< 0:4.18.0-348.7.1.el8_5
kernel-zfcpdump-debuginfo< 0:4.18.0-348.7.1.el8_5
kernel-zfcpdump-devel< 0:4.18.0-348.7.1.el8_5
kernel-zfcpdump-modules< 0:4.18.0-348.7.1.el8_5
kernel-zfcpdump-modules-extra< 0:4.18.0-348.7.1.el8_5
perf< 0:4.18.0-348.7.1.el8_5
perf-debuginfo< 0:4.18.0-348.7.1.el8_5
python3-perf< 0:4.18.0-348.7.1.el8_5
python3-perf-debuginfo< 0:4.18.0-348.7.1.el8_5

Show all 51

Debian2 products

linux< 5.14.12-1
debian_linuxEOL9.0 | 10.0

Linux1 product

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

4 vendors · 117 products

References

21 links

bugzilla.redhat.com/show_bug.cgi?id=2013242X Refsource MISCREPORTIssue TrackingThird Party Advisory
lore.kernel.org/all/20211011134508.748956131%40linuxfoundation.org/X Refsource MISC
lists.debian.org/debian-lts-announce/2022/03/msg00012.htmlMailing ListX Refsource MLISTThird Party Advisory
www.debian.org/security/2022/dsa-5096Vendor AdvisoryX Refsource DEBIANThird Party Advisory
access.redhat.com/errata/RHSA-2021:5227Advisory
access.redhat.com/security/updates/classification/ARTICLE
security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_5227.jsonAdvisory
access.redhat.com/security/cve/CVE-2021-20321REPORT
www.cve.org/CVERecord?id=CVE-2021-20321AdvisoryREPORT
nvd.nist.gov/vuln/detail/CVE-2021-20321AdvisoryOval

Show all 21 references

lore.kernel.org/all/20211011134508.748956131@linuxfoundation.org/ARTICLE
access.redhat.com/errata/RHSA-2021:5241Advisory
security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_5241.jsonAdvisory
ubuntu.com/security/CVE-2021-20321REPORT
git.kernel.org/linus/a295aef603e109a47af355477326bd41151765b6REPORT
ubuntu.com/security/notices/USN-5208-1Advisory
ubuntu.com/security/notices/USN-5209-1Advisory
ubuntu.com/security/notices/USN-5210-1Advisory
ubuntu.com/security/notices/USN-5218-1Advisory
ubuntu.com/security/notices/USN-6221-1Advisory
security-tracker.debian.org/tracker/CVE-2021-20321Advisory