CVE-2021-26931: debian debian_linux

Modified

AliasesUBUNTU-CVE-2021-26931DEBIAN-CVE-2021-26931

Published 17-02-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-26931 is a medium (CVSS 5.5) vulnerability in debian debian_linux. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 46.4% of scored vulnerabilities.

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

0.56%

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

17-02-2021
PublishedVulnerability first disclosed.
03-08-2024
Last modifiedVulnerability information updated.

Description

An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen. Block, net, and SCSI backends consider certain errors a plain bug, deliberately causing a kernel crash. For errors potentially being at least under the influence of guests (such as out of memory conditions), it isn't correct to assume a plain bug. Memory allocations potentially causing such crashes occur only when Linux is running in PV mode, though. This affects drivers/block/xen-blkback/blkback.c and drivers/xen/xen-scsiback.c.

CVSS metrics

4 scores · 3 sources · 2 versions

v3.15.5v2.01.9

EPSS trend

Probability

0.56%

Chance of exploitation in the next 30 days

Percentile

46%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.56% 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-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Affected systems

Version check

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

Ubuntu49 products

linuxAll versions (No fix recorded) | < 4.4.0-208.240 | < 4.15.0-143.147 | < 5.4.0-71.79
linux-aws< 4.4.0-1090.94 | < 4.4.0-1126.140 | < 4.15.0-1102.109 | < 5.4.0-1043.45
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.3All versions (No fix recorded)
linux-aws-5.4< 5.4.0-1043.45~18.04.1

linux-aws-fips< 4.15.0-2044.46 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1102.109~16.04.1
linux-azure< 4.15.0-1114.127~14.04.1 | < 4.15.0-1114.127~16.04.1 | All versions (No fix recorded) | < 5.4.0-1044.46
linux-azure-4.15< 4.15.0-1114.127
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1044.46~18.04.1
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fde-5.15< 5.15.0-1114.123~20.04.1
linux-azure-fips< 4.15.0-2026.29 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-dell300x< 4.15.0-1018.22
linux-fips< 4.4.0-1060.66 | All versions (No fix recorded) | < 4.15.0-1059.67
linux-gcp< 4.15.0-1099.112~16.04.1 | All versions (No fix recorded) | < 5.4.0-1041.44
linux-gcp-4.15< 4.15.0-1099.112
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1041.44~18.04.1
linux-gcp-edgeAll versions (No fix recorded)
linux-gcp-fipsAll versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1041.43
linux-gke-4.15All versions (No fix recorded)
linux-gke-5.4< 5.4.0-1040.42~18.04.1
linux-gkeop< 5.4.0-1013.14
linux-gkeop-5.4< 5.4.0-1013.14~18.04.1
linux-hwe< 4.15.0-143.147~16.04.3 | All versions (No fix recorded)
linux-hwe-5.4< 5.4.0-71.79~18.04.1
linux-hwe-5.8< 5.8.0-53.60~20.04.1
linux-hwe-edgeAll versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvm< 4.4.0-1091.100 | < 4.15.0-1091.93 | < 5.4.0-1037.38
linux-lts-xenial< 4.4.0-208.240~14.04.1
linux-oemAll versions (No fix recorded)
linux-oem-5.10< 5.10.0-1017.18
linux-oem-5.6All versions (No fix recorded)
linux-oracle< 4.15.0-1071.79~16.04.1 | < 4.15.0-1071.79 | < 5.4.0-1042.45
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1042.45~18.04.1
linux-raspi< 5.4.0-1033.36
linux-raspi-5.4< 5.4.0-1033.36~18.04.1
linux-raspi-realtimeAll versions (No fix recorded)
linux-raspi2< 4.4.0-1150.161 | < 4.15.0-1085.90 | All versions (No fix recorded)
linux-realtimeAll versions (No fix recorded)
linux-riscvAll versions (No fix recorded)
linux-riscv-5.8< 5.8.0-25.27~20.04.1
linux-snapdragon< 4.4.0-1154.164 | < 4.15.0-1102.111

Show all 49

Debian2 products

linux< 5.10.19-1
debian_linuxEOL9.0

Fedoraproject1 product

fedoraEOL32 | 33

Linux1 product

linux_kernel≥ 2.6.39, ≤ 5.10.16

4 vendors · 53 products

References

19 links

xenbits.xen.org/xsa/advisory-362.htmlPatchThird Party Advisory
lists.fedoraproject.org/archives/…Vendor Advisory
lists.fedoraproject.org/archives/…Vendor Advisory
lists.debian.org/debian-lts-announce/2021/03/msg00010.htmlMailing ListThird Party Advisory
security.netapp.com/advisory/ntap-20210326-0001/Third Party Advisory
lists.debian.org/debian-lts-announce/2021/03/msg00035.htmlMailing ListThird Party Advisory
git.kernel.org/cgit/…
git.kernel.org/cgit/…
git.kernel.org/cgit/…
ubuntu.com/security/CVE-2021-26931REPORT

Show all 19 references

xenbits.xen.org/xsa/advisory-362.htmlREPORT
www.openwall.com/lists/oss-security/2021/02/16/4REPORT
ubuntu.com/security/notices/USN-4904-1Advisory
ubuntu.com/security/notices/USN-4909-1Advisory
ubuntu.com/security/notices/USN-4946-1Advisory
ubuntu.com/security/notices/USN-4949-1Advisory
www.cve.org/CVERecord?id=CVE-2021-26931REPORT
security-tracker.debian.org/tracker/CVE-2021-26931Advisory
nvd.nist.gov/vuln/detail/CVE-2021-26931OvalAdvisory