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Fencer Intel
medium 6.1

CVE-2020-23839 json

A Reflected Cross-Site Scripting (XSS) vulnerability in GetSimple CMS v3.3.16, in the admin/index.php login portal webpage, allows remote a…

published 6y ago modified 4mo ago also EUVD-2020-16577

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
10.5%
EPSS 10.5% chance of exploitation in 30 days, percentile 95%
public exploits
1
Exploit-DB

Summary

A Reflected Cross-Site Scripting (XSS) vulnerability in GetSimple CMS v3.3.16, in the admin/index.php login portal webpage, allows remote attackers to execute JavaScript code in the client's browser and harvest login credentials after a client clicks a link, enters credentials, and submits the login form.

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Timeline

  1. Published
  2. First public exploit (EDB-49726)

Exploit prediction

10.46% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-49726 GetSimple CMS 3.3.16 - Persistent Cross-Site Scripting webapps, 2021-03-30
  • github.com https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1330 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.