CVE-2020-21055Network attack vector

Arbitrary file renaming via unsanitized path parameters

Published May 20, 2021 · Updated Aug 4, 2024

Path traversal in FusionPBX 4.5.7 allows remote authenticated users to rename arbitrary system files through a crafted web request. The app/edit/filerename.php endpoint concatenates unsanitized folder, filename, and newfilename URL parameters and passes the resulting paths to PHP's rename() operation. Any authenticated account that can reach the endpoint can move or rename files accessible to the web-service process, altering filesystem integrity without reading their contents.

CVSS severity6.5
Medium
EPSS probability1.18%
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 FusionPBX 4.5.7 allows remote authenticated users to rename arbitrary system files through a crafted web request. The app/edit/filerename.php endpoint concatenates unsanitized folder, filename, and newfilename URL parameters and passes the resulting paths to PHP's rename() operation. Any authenticated account that can reach the endpoint can move or rename files accessible to the web-service process, altering filesystem integrity without reading their contents.

The record

CVE
CVE-2020-21055
Published
May 20, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-22, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:P/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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')
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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