CVE-2021-3178: Path Traversal
DISPUTED 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) nosubtreecheck default behavior.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.25-1Fixed in 6.12.27-1
Event History
Frequently Asked Questions
What is the severity of CVE-2021-3178?
CVE-2021-3178 is considered a moderate severity vulnerability that can allow remote attackers to traverse the filesystem.
How do I fix CVE-2021-3178?
To remediate CVE-2021-3178, update the Linux kernel to version 5.10.223-1, 5.10.226-1 or later.
What software is affected by CVE-2021-3178?
CVE-2021-3178 affects the Linux kernel up to version 5.10.8 and specific distributions like Fedora 33 and Debian 9.0.
Can CVE-2021-3178 be exploited remotely?
Yes, CVE-2021-3178 can be exploited remotely via the READDIRPLUS functionality in NFS exports.
Is this vulnerability still a concern if I am using a patched version?
If you are using a patched version of the Linux kernel, the concerns related to CVE-2021-3178 should be mitigated.