Skip to content
Fencer Intel
medium 6.3

CVE-2021-4097 json

CRLF Injection in phpservermon/phpservermon

published 4y ago modified 4mo ago also GHSA-8qv8-fq5w-p966 , EUVD-2021-2485

cvss
6.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits
0
none known

Summary

phpservermon is vulnerable to Improper Neutralization of CRLF Sequences

Patch / fix

  • phpservermon phpservermon/phpservermon 3.6.0

Is CVE-2021-4097 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • huntr.dev https://huntr.dev/bounties/d617ced7-be06-4e34-9db0-63d45c003a43 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 6.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N
GitHub 3.0 6.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Affected packages

ecosystem package affected fixed in
packagist phpservermon/phpservermon
<=3.5.2
 no fix listed

Affected products

  • phpservermon phpservermon/phpservermon

Classification

Weakness
  • CWE-93 Improper Neutralization of CRLF Sequences

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.