CVE-2020-27171: canonical ubuntu_linux Off-by-one Error

Modified

AliasesUBUNTU-CVE-2020-27171DEBIAN-CVE-2020-27171

Published 20-03-2021Last modified 08-10-2026

Vulnerability summary

CVE-2020-27171 is a medium (CVSS 6.0) Off-by-one Error vulnerability in canonical ubuntu_linux. EPSS estimates a 0.58% chance of exploitation in the next 30 days, higher than 47.5% of scored vulnerabilities.

Priority

Routine

Not severe (CVSS 6, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

6.0/10

010

Medium · v3.1 (NVD)

EPSS score

0.58%

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

20-03-2021
PublishedVulnerability first disclosed.
08-10-2026
Last modifiedVulnerability information updated.

Description

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.

CVSS metrics

4 scores · 3 sources · 2 versions

v3.16.0v2.03.6

EPSS trend

Probability

0.58%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.58% 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-193Off-by-one ErrorA product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

Affected systems

Version check

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

Ubuntu50 products

linuxAll versions (No fix recorded) | < 4.15.0-140.144 | < 5.4.0-70.78
linux-awsAll versions (No fix recorded) | < 4.15.0-1097.104 | < 5.4.0-1041.43
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.3All versions (No fix recorded)
linux-aws-5.4< 5.4.0-1041.43~18.04.1

linux-aws-fips< 4.15.0-2040.42 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1097.104~16.04.1
linux-azure< 4.15.0-1111.123~14.04.1 | < 4.15.0-1111.123~16.04.1 | All versions (No fix recorded) | < 5.4.0-1043.45
linux-azure-4.15< 4.15.0-1111.123
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1043.45~18.04.1
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fips< 4.15.0-2023.26 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-dell300x< 4.15.0-1015.19
linux-fipsAll versions (No fix recorded) | < 4.15.0-1056.64
linux-gcp< 4.15.0-1096.109~16.04.1 | All versions (No fix recorded) | < 5.4.0-1040.43
linux-gcp-4.15< 4.15.0-1096.109
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1040.43~18.04.1
linux-gcp-edgeAll versions (No fix recorded)
linux-gcp-fipsAll versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1039.41
linux-gke-4.15All versions (No fix recorded)
linux-gke-5.3< 5.3.0-1041.44
linux-gke-5.4< 5.4.0-1039.41~18.04.1
linux-gkeop< 5.4.0-1012.13
linux-gkeop-5.4< 5.4.0-1012.13~18.04.1
linux-hwe< 4.15.0-140.144~16.04.1 | < 5.3.0-72.68
linux-hwe-5.4< 5.4.0-70.78~18.04.1
linux-hwe-5.8< 5.8.0-48.54~20.04.1
linux-hwe-edgeAll versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvmAll versions (No fix recorded) | < 4.15.0-1088.90 | < 5.4.0-1036.37
linux-lts-xenialAll versions (No fix recorded)
linux-oemAll versions (No fix recorded)
linux-oem-5.10< 5.10.0-1019.20
linux-oem-5.6< 5.6.0-1052.56
linux-oracle< 4.15.0-1068.76~16.04.1 | < 4.15.0-1068.76 | < 5.4.0-1041.44
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1041.44~18.04.1
linux-raspi< 5.4.0-1032.35
linux-raspi-5.4< 5.4.0-1032.35~18.04.1
linux-raspi-realtimeAll versions (No fix recorded)
linux-raspi2< 4.15.0-1082.87 | All versions (No fix recorded)
linux-raspi2-5.3< 5.3.0-1038.40
linux-realtimeAll versions (No fix recorded)
linux-riscvAll versions (No fix recorded)
linux-riscv-5.8< 5.8.0-20.22~20.04.1
linux-snapdragon< 4.15.0-1099.108

Show all 50

Debian2 products

linux< 5.10.24-1
debian_linuxEOL9.0

Canonical1 product

ubuntu_linuxEOL14.04 | 16.04 | 18.04 | 20.04

Fedoraproject1 product

fedoraEOL32 | 33 | 34

Linux1 product

linux_kernel< 5.11.8

5 vendors · 55 products

References

15 links

cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8X Refsource MISCPatchVendor Advisory
www.openwall.com/lists/oss-security/2021/03/19/3X Refsource MISCREPORTMailing ListPatchThird Party Advisory
git.kernel.org/pub/…X Refsource MISCPatchVendor Advisory
lists.fedoraproject.org/archives/…Vendor AdvisoryX Refsource FEDORA
lists.fedoraproject.org/archives/…Vendor AdvisoryX Refsource FEDORA
www.openwall.com/lists/oss-security/2021/03/24/5Mailing ListX Refsource MLISTThird Party Advisory
lists.fedoraproject.org/archives/…Vendor AdvisoryX Refsource FEDORA
lists.debian.org/debian-lts-announce/2021/03/msg00035.htmlMailing ListX Refsource MLISTThird Party Advisory
packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.htmlX Refsource MISCThird Party AdvisoryVDB Entry
ubuntu.com/security/CVE-2020-27171REPORT

Show all 15 references

ubuntu.com/security/notices/USN-4887-1Advisory
ubuntu.com/security/notices/USN-4890-1Advisory
www.cve.org/CVERecord?id=CVE-2020-27171REPORT
security-tracker.debian.org/tracker/CVE-2020-27171Advisory
nvd.nist.gov/vuln/detail/CVE-2020-27171OvalAdvisory