ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2023-53956

Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager.

Published Dec 19, 2025 · catalog updated Apr 7, 2026 · Flatnux 2021-03.25 contains an

Last checked Nov 2, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2023-53956. EPSS is 0.77%. Act only if a listed version of Flatnux 2021-03.25 contains an is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Flatnux 2021-03.25 contains an).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High8.7
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.77%
Remediation
Vendor / distro source
Affected products
vendor altervista flatnux 2021-03.25

Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager. Attackers with admin credentials can upload malicious PHP scripts to the web root directory, enabling remote code execution on the server.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor altervista flatnux 2021-03.252021-03.25

How to fix CVE-2023-53956

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2023-53956. EPSS is 0.77%. Act only if a listed version of Flatnux 2021-03.25 contains an is installed.

Which versions are affected?

Compare what you have installed with altervista flatnux 2021-03.25 2021-03.25. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.77%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 19, 2025 · EUVD

    Detected

    Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager. Attackers with admin credentials can upload malicious PHP scripts to the web root directory, enabling remote code execution on the server.

  2. Apr 7, 2026 · EUVD

    Updated

    Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager. Attackers with admin credentials can upload malicious PHP scripts to the web root directory, enabling remote code execution on the server.

Sources

  • CVE.orgVulnerability recordCVE-2023-53956

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2023-53956

    30-day exploitation probability 0.77%

    first.org
  • EUVDVulnerability recordEUVD-2025-204594

    Flatnux 2021-03.25 contains an authenticated file upload vulnerability that allows administrative users to upload arbitrary PHP files through the file manager. Attackers with admin credentials can upload malicious PHP scripts to the web root directory, enabling remote code execut

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 2, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 2, 2026
  • CVE.orgOct 30, 2026
  • EUVDOct 30, 2026