What’s Vulnerable › Vulnerabilities

CVE-2021-3178

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-01-19 · updated 2026-06-17
• Weakness: CWE-22

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

Affected products

• Debian Linux: 9.0
• Fedoraproject Fedora: 33
• Linux kernel: through 5.10.8

References

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=51b2ee7d006a736a9126e8111d1f24e4fd0afaa6
• https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5SGB7TNDVQEOJ7NVTGX56UWHDNQM5TRC/
• https://patchwork.kernel.org/project/linux-nfs/patch/20210111210129.GA11652%40fieldses.org/
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=51b2ee7d006a736a9126e8111d1f24e4fd0afaa6
• https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5SGB7TNDVQEOJ7NVTGX56UWHDNQM5TRC/
• https://patchwork.kernel.org/project/linux-nfs/patch/20210111210129.GA11652%40fieldses.org/

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