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Fencer Intel
medium 6.1

CVE-2021-25033 json

Noptin < 1.6.5 - Open Redirect

published 4y ago modified 4mo ago also EUVD-2021-11945

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.3%
EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits
0
none known, plus a Nuclei check

Summary

The WordPress Newsletter Plugin WordPress plugin before 1.6.5 does not validate the to parameter before redirecting the user to its given value, leading to an open redirect issue

Patch / fix

  • noptin noptin 1.6.5

Is CVE-2021-25033 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

2.30% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template Noptin < 1.6.5 - Open Redirect nuclei detection template
  • wpscan.com https://wpscan.com/vulnerability/c2d2384c-41b9-4aaf-b918-c1cfda58af5c 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 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N

Affected products

  • Unknown WordPress Newsletter Plugin – Noptin

Classification

Weakness
  • CWE-601 URL Redirection to Untrusted Site
Technology feeds

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.