CVE-2020-27833Public exploitNetwork attack vector

Arbitrary file write via chained symlinks

Published May 14, 2021 · Updated Aug 4, 2024

Zip Slip in oc in Red Hat OpenShift CLI 4.7.0-202104250659.p0.git.95881af and earlier allows remote authenticated users to overwrite files via crafted tar images. The unpackLayer routine checks each symlink target without resolving previously created links, so chained links escape the extraction directory and redirect writes or reads outside it. Exploitation requires a user to run oc image extract on an attacker-controlled raw container image; resulting file overwrite can enable code execution with the CLI process permissions.

CVSS severity7.1
High
EPSS probability1.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Zip Slip in oc in Red Hat OpenShift CLI 4.7.0-202104250659.p0.git.95881af and earlier allows remote authenticated users to overwrite files via crafted tar images. The unpackLayer routine checks each symlink target without resolving previously created links, so chained links escape the extraction directory and redirect writes or reads outside it. Exploitation requires a user to run oc image extract on an attacker-controlled raw container image; resulting file overwrite can enable code execution with the CLI process permissions.

The record

CVE
CVE-2020-27833
Published
May 14, 2021
Updated
Aug 4, 2024
Vendor
Red Hat
Product
OpenShift CLI
Classifications
CWE-20, CWE-59, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=up to & including openshift-clients-4.7.0-202104250659.p0.git.95881af

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Red Hat · OpenShift CLIversion=up to & including openshift-clients-4.7.0-202104250659.p0.git.95881af

Published CVSS scores

7.1NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
4.6NVDAV:N/AC:H/Au:S/C:P/I:P/A:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-59Improper Link Resolution Before File Access
T1203Exploitation for Client Execution

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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