CVE-2013-20001Public exploitNetwork attack vector

Unauthenticated NFS data exposure via IPv6 host misparsing

Published Feb 12, 2021 · Updated Nov 3, 2025

Improper input validation in OpenZFS through 2.0.3 allows remote attackers to read NFS shares restricted to IPv6 clients. In lib/libshare/os/linux/nfs.c, foreach_nfs_host_cb splits each host at the first colon, so bracketed IPv6 literals are truncated instead of passed intact to exportfs. The share must use sharenfs with an IPv6 host restriction; the malformed export drops that restriction and permits unauthenticated network access.

CVSS severity7.5
High
EPSS probability2.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in OpenZFS through 2.0.3 allows remote attackers to read NFS shares restricted to IPv6 clients. In lib/libshare/os/linux/nfs.c, foreach_nfs_host_cb splits each host at the first colon, so bracketed IPv6 literals are truncated instead of passed intact to exportfs. The share must use sharenfs with an IPv6 host restriction; the malformed export drops that restriction and permits unauthenticated network access.

The record

CVE
CVE-2013-20001
Published
Feb 12, 2021
Updated
Nov 3, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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