CVE-2021-33558

Name: CVE-2021-33558
Creator: NVD / NIST
Published: 2021-05-27T11:15:07.373+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 10.33%

Last modified Jun 17, 2026

CVE-2021-33558 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Boa 0.94.13 allows remote attackers to obtain sensitive information via a misconfiguration involving backup.html, preview.html, js/log.js, log.html, email.html, online-users.html, and config.js. NOTE: multiple third parties report that this is a site-specific issue because those files are not part of Boa.. EPSS estimates a 10.33% chance of exploitation in the next 30 days.

Description

Boa 0.94.13 allows remote attackers to obtain sensitive information via a misconfiguration involving backup.html, preview.html, js/log.js, log.html, email.html, online-users.html, and config.js. NOTE: multiple third parties report that this is a site-specific issue because those files are not part of Boa.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

10.33%

95.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Boa	Boa	0.94.13

References

https://github.com/mdanzaruddin/CVE-2021-33558.Exploit, Third Party Advisory
https://github.com/mdanzaruddin/CVE-2021-33558./issues/1Issue Tracking, Third Party Advisory
https://sourceforge.net/projects/boa/files/boa/0.94.13/Release Notes, Third Party Advisory
https://github.com/mdanzaruddin/CVE-2021-33558.Exploit, Third Party Advisory
https://github.com/mdanzaruddin/CVE-2021-33558./issues/1Issue Tracking, Third Party Advisory
https://sourceforge.net/projects/boa/files/boa/0.94.13/Release Notes, Third Party Advisory

Timeline

Published: May 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33558?

How severe is CVE-2021-33558?

CVE-2021-33558 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 10.33% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33558?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-33558?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST