CVE-2020-23171Public exploit

Arbitrary file write via traversal archive entries

Published Aug 10, 2021 · Updated Aug 4, 2024

Path traversal in all versions of the Nim-lang zip library allows attackers to write outside the extraction directory through crafted ZIP entries. The extractAll procedure joins each archive member name returned by walkFiles directly to the destination path without validating the combined path. No authentication is required, but an application must extract an attacker-supplied archive; writes remain limited by that application's filesystem permissions.

CVSS severity5.5
Medium
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in all versions of the Nim-lang zip library allows attackers to write outside the extraction directory through crafted ZIP entries. The extractAll procedure joins each archive member name returned by walkFiles directly to the destination path without validating the combined path. No authentication is required, but an application must extract an attacker-supplied archive; writes remain limited by that application's filesystem permissions.

The record

CVE
CVE-2020-23171
Published
Aug 10, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-610, CAPEC-219, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-610Externally Controlled Reference to a Resource in Another Sphere
CAPEC-219XML Routing Detour Attacks
T1204.002Malicious File

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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