CVE-2021-32760Network attack vector

Host permission changes via archive symlink traversal

Published Jul 19, 2021 · Updated Nov 19, 2024

Improper permission handling in containerd 1.4.7 and earlier and 1.5.0 through 1.5.3 allows remote attackers to alter host file modes. During archive extraction, handleLChmod checks a hard-link target using the untrusted header link name, then applies chmod to a resolved path that can traverse a symlink to an existing host file. A user or cooperating process must pull and unpack the crafted image; the flaw changes permission bits but does not itself read, modify, or execute file contents.

CVSS severity5.0
Medium
EPSS probability1.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper permission handling in containerd 1.4.7 and earlier and 1.5.0 through 1.5.3 allows remote attackers to alter host file modes. During archive extraction, handleLChmod checks a hard-link target using the untrusted header link name, then applies chmod to a resolved path that can traverse a symlink to an existing host file. A user or cooperating process must pull and unpack the crafted image; the flaw changes permission bits but does not itself read, modify, or execute file contents.

The record

CVE
CVE-2021-32760
Published
Jul 19, 2021
Updated
Nov 19, 2024
Vendor
containerd
Product
containerd
Classifications
CWE-668, CWE-732, T1222.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 19, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 1.4.7
  2. Affected versionversion=>= 1.5.0, <= 1.5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

containerd · containerdversion=<= 1.4.7; version=>= 1.5.0, <= 1.5.3

Published CVSS scores

6.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
5.0GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
CWE-732Incorrect Permission Assignment for Critical Resource
T1222.002File and Directory Permissions Modification: Linux and Mac File and Directory Permissions Modification

Public exploit references

No public exploit references are available in this record.

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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