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Vulnerability record · CVE-2021-4171 · published 17 January 2022

CVE-2021-4171: Janeczku calibre-web vulnerability

JJaneczku · Calibre Web

calibre-web is vulnerable to Business Logic Errors

9.8 CVSS 3.1 Critical EPSS 1.4% · top 28.9% CWE-840 · CWE-840
9.8CVSS 3.1 base score, v2 7.5
1.4%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

calibre-web is vulnerable to Business Logic Errors

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

Affected products

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

References

LinkTags
https://github.com/janeczku/calibre-web/commit/3e0d8763c377d2146462811e3e4ccf13f0d312ce PatchThird Party Advisory
https://huntr.dev/bounties/1117f439-133c-4563-afb2-6cd80607bd5c ExploitPatchThird Party Advisory
https://github.com/janeczku/calibre-web/commit/3e0d8763c377d2146462811e3e4ccf13f0d312ce PatchThird Party Advisory
https://huntr.dev/bounties/1117f439-133c-4563-afb2-6cd80607bd5c ExploitPatchThird Party Advisory

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Related vulnerabilities

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

9.9CVE-2022-0939Janeczku calibre-web server-side request forgery (ssrf) vulnerabilityServer-Side Request Forgery (SSRF) in GitHub repository janeczku/calibre-web prior to 0.6.18.EPSS 1.1%9.9CVE-2022-0767Janeczku calibre-web server-side request forgery (ssrf) vulnerabilityServer-Side Request Forgery (SSRF) in GitHub repository janeczku/calibre-web prior to 0.6.17.EPSS 0.99%9.8CVE-2023-2106Janeczku calibre-web weak password requirements vulnerabilityWeak Password Requirements in GitHub repository janeczku/calibre-web prior to 0.6.20.EPSS 0.75%9.8CVE-2022-2525Janeczku calibre-web improper restriction of authentication attempts vulnerabilityImproper Restriction of Excessive Authentication Attempts in GitHub repository janeczku/calibre-web prior to 0.6.20.EPSS 0.77%9.8CVE-2022-30765Janeczku calibre-web sql injection vulnerabilityCalibre-Web before 0.6.18 allows user table SQL Injection.EPSS 1.2%9.8CVE-2022-0766Janeczku calibre-web server-side request forgery (ssrf) vulnerabilityServer-Side Request Forgery (SSRF) in GitHub repository janeczku/calibre-web prior to 0.6.17.EPSS 1.3%9.8CVE-2022-0339Janeczku calibre-web server-side request forgery (ssrf) vulnerabilityServer-Side Request Forgery (SSRF) in Pypi calibreweb prior to 0.6.16.EPSS 0.96%9.8CVE-2020-12627Janeczku calibre-web hard-coded credentials vulnerabilityCalibre-Web 0.6.6 allows authentication bypass because of the 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT' hardcoded secret key.EPSS 1.4%

Source: NIST National Vulnerability Database (record CVE-2021-4171), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.