Path Traversal in Linux Kernel

CVE-2021-3178

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

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.024 (82.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-3178?
CVE-2021-3178 is a medium-severity vulnerability in Linux Kernel, classified under Path Traversal. CVSS score: 6.5/10. Published 2021-01-19.
How severe is CVE-2021-3178?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-3178 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.