CVE-2021-41279Network attack vector

Host file writes via unchecked ZIP entry paths

Published Nov 26, 2021 · Updated Aug 4, 2024

Path traversal in baserCMS 4.5.3 and earlier allows remote authenticated users to extract crafted ZIP entries outside the intended directory. The management upload path passes attacker-controlled ZIP entry paths to SimpleZip extraction without constraining them beneath the destination. Upload privilege is required; successful traversal places archive content at host paths writable by the web-service account.

CVSS severity7.7
High
EPSS probability1.57%
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 baserCMS 4.5.3 and earlier allows remote authenticated users to extract crafted ZIP entries outside the intended directory. The management upload path passes attacker-controlled ZIP entry paths to SimpleZip extraction without constraining them beneath the destination. Upload privilege is required; successful traversal places archive content at host paths writable by the web-service account.

The record

CVE
CVE-2021-41279
Published
Nov 26, 2021
Updated
Aug 4, 2024
Vendor
baserCMS Users Community
Product
baserCMS
Classifications
CWE-22, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 26, 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=< 4.5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

baserCMS Users Community · baserCMSversion=< 4.5.3

Published CVSS scores

9.0National Institute of Standards and TechnologyAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8National Institute of Standards and TechnologyCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.7GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

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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