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Vulnerability record · CVE-2021-33558 · published 27 May 2021

CVE-2021-33558: Boa vulnerability

Boa · Boa

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.

7.5 CVSS 3.1 High EPSS 12% · top 3.9%
7.5CVSS 3.1 base score, v2 5.0
12%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/mdanzaruddin/CVE-2021-33558. ExploitThird Party Advisory
https://github.com/mdanzaruddin/CVE-2021-33558./issues/1 Issue TrackingThird Party Advisory
https://sourceforge.net/projects/boa/files/boa/0.94.13/ Release NotesThird Party Advisory
https://github.com/mdanzaruddin/CVE-2021-33558. ExploitThird Party Advisory
https://github.com/mdanzaruddin/CVE-2021-33558./issues/1 Issue TrackingThird Party Advisory
https://sourceforge.net/projects/boa/files/boa/0.94.13/ Release NotesThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2022-44117Boa sql injection vulnerabilityBoa 0.94.14rc21 is vulnerable to SQL Injection via username. NOTE: the is disputed by multiple third parties because Boa does not ship with any suppo…EPSS 0.73%9.8CVE-2018-21027Boa memory buffer overflow vulnerabilityBoa through 0.94.14rc21 allows remote attackers to trigger an out-of-memory (OOM) condition because malloc is mishandled.EPSS 2.4%7.5CVE-2018-21028Boa vulnerabilityBoa through 0.94.14rc21 allows remote attackers to trigger a memory leak because of missing calls to the free function.EPSS 2.1%7.5CVE-2017-9833Boa wapopen path traversal via FILECAMERA reads files as rootA path traversal flaw is reported in /cgi-bin/wapopen in Boa 0.94.14rc21, where the FILECAMERA GET variable accepts "../.." sequences and can read fi…EPSS 68%analysed7.5CVE-2016-9564Boa improper input validation vulnerabilityBuffer overflow in send_redirect() in Boa Webserver 0.92r allows remote attackers to DoS via an HTTP GET request requesting a long URI with only '/' …EPSS 1.4%5.3CVE-2022-45956Boa incorrect authorization vulnerabilityBoa Web Server versions 0.94.13 through 0.94.14 fail to validate the correct security constraint on the HEAD HTTP method allowing everyone to bypass …EPSS 0.82%5.0CVE-2009-4496Boa improper input validation vulnerabilityBoa 0.94.14rc21 writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's title,…EPSS 12%

Source: NIST National Vulnerability Database (record CVE-2021-33558), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.