CVE-2021-41772Public exploitNetwork attack vector

Service crash via invalid ZIP entry names

Published Nov 8, 2021 · Updated Aug 4, 2024

Denial of service in Go archive/zip 1.16.0 through 1.16.9 and 1.17.0 through 1.17.2 allows attackers to crash applications via crafted ZIP input. Reader.Open accepts entry names made solely of slashes or dot-dot elements, cleans them to an empty name, and its split helper indexes before the start of the string, triggering a runtime panic. The crash requires an application to pass attacker-controlled ZIP contents to Reader.Open or call it with an empty name; no confidentiality or integrity impact is reported.

CVSS severity7.5
High
EPSS probability3.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Go archive/zip 1.16.0 through 1.16.9 and 1.17.0 through 1.17.2 allows attackers to crash applications via crafted ZIP input. Reader.Open accepts entry names made solely of slashes or dot-dot elements, cleans them to an empty name, and its split helper indexes before the start of the string, triggering a runtime panic. The crash requires an application to pass attacker-controlled ZIP contents to Reader.Open or call it with an empty name; no confidentiality or integrity impact is reported.

The record

CVE
CVE-2021-41772
Published
Nov 8, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 8, 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?

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

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

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 exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499.004Application or System Exploitation

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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