CVE-2021-3178: debian debian_linux

Modified

AliasesUBUNTU-CVE-2021-3178DEBIAN-CVE-2021-3178

Published 19-01-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-3178 is a medium (CVSS 6.5) vulnerability in debian debian_linux. EPSS estimates a 2.45% chance of exploitation in the next 30 days, higher than 84.3% of scored vulnerabilities.

Priority

Routine

Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

6.5/10

010

Medium · v3.1 (NVD)

EPSS score

2.45%

0%100%

Low · +0.03 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 8 · Related 5

DLA-2586-1 MGASA-2021-0058 MGASA-2021-0061 USN-4876-1 USN-4877-1 USN-4878-1+2 more

Timeline

19-01-2021
PublishedVulnerability first disclosed.
03-08-2024
Last modifiedVulnerability information updated.

Description

fs/nfsd/nfs3xdr.c in the Linux kernel through 5.10.8, when there is an NFS export of a subdirectory of a filesystem, allows remote attackers to traverse to other parts of the filesystem via READDIRPLUS. NOTE: some parties argue that such a subdirectory export is not intended to prevent this attack; see also the exports(5) no_subtree_check default behavior

CVSS metrics

4 scores · 3 sources · 2 versions

v3.16.5v2.05.5

EPSS trend

Probability

2.45%

Chance of exploitation in the next 30 days

Percentile

84%

Versus all other CVEs

30-day change

Increase +0.03 pp

From 2.42% 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-22Improper Limitation of a Pathname to a Restricted DirectoryThe product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Affected systems

Version check

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

Ubuntu49 products

linuxAll versions (No fix recorded) | < 4.4.0-204.236 | < 4.15.0-137.141 | < 5.4.0-67.75
linux-aws< 4.4.0-1087.91 | < 4.4.0-1123.137 | < 4.15.0-1095.102 | < 5.4.0-1039.41
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.3All versions (No fix recorded)
linux-aws-5.4< 5.4.0-1039.41~18.04.1

linux-aws-fips< 4.15.0-2038.40 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1095.102~16.04.1
linux-azure< 4.15.0-1109.121~14.04.1 | < 4.15.0-1109.121~16.04.1 | All versions (No fix recorded) | < 5.4.0-1041.43
linux-azure-4.15< 4.15.0-1109.121
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1041.43~18.04.1
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fde-5.15< 5.15.0-1114.123~20.04.1
linux-azure-fips< 4.15.0-2021.24 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-dell300x< 4.15.0-1013.17
linux-fips< 4.4.0-1057.63 | All versions (No fix recorded) | < 4.15.0-1054.62
linux-gcp< 4.15.0-1094.107~16.04.1 | All versions (No fix recorded) | < 5.4.0-1038.41
linux-gcp-4.15< 4.15.0-1094.107
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1038.41~18.04.1
linux-gcp-edgeAll versions (No fix recorded)
linux-gcp-fipsAll versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1037.39
linux-gke-4.15All versions (No fix recorded)
linux-gke-5.4< 5.4.0-1037.39~18.04.1
linux-gkeop< 5.4.0-1011.12
linux-gkeop-5.4< 5.4.0-1011.12~18.04.2
linux-hwe< 4.15.0-137.141~16.04.1 | All versions (No fix recorded)
linux-hwe-5.4< 5.4.0-67.75~18.04.1
linux-hwe-5.8< 5.8.0-49.55~20.04.1
linux-hwe-edgeAll versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvm< 4.4.0-1089.98 | < 4.15.0-1086.88 | < 5.4.0-1034.35
linux-lts-xenial< 4.4.0-204.236~14.04.1
linux-oemAll versions (No fix recorded)
linux-oem-5.10< 5.10.0-1014.15
linux-oem-5.6< 5.6.0-1053.57
linux-oracle< 4.15.0-1066.74~16.04.1 | < 4.15.0-1066.74 | < 5.4.0-1039.42
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1039.42~18.04.1
linux-raspi< 5.4.0-1030.33
linux-raspi-5.4< 5.4.0-1030.33~18.04.1
linux-raspi-realtimeAll versions (No fix recorded)
linux-raspi2< 4.4.0-1147.157 | < 4.15.0-1080.85 | All versions (No fix recorded)
linux-realtimeAll versions (No fix recorded)
linux-riscvAll versions (No fix recorded)
linux-riscv-5.8< 5.8.0-22.24~20.04.1
linux-snapdragon< 4.4.0-1151.161 | < 4.15.0-1097.106