Cyber Resilience

CVE-2021-3988

MediumPublic PoC

Published: 15 November 2024

Published
15 November 2024
Modified
19 November 2024
KEV Added
Patch
CVSS Score v3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0024 47.1th percentile
Risk Priority 12 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3988 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Janeczku Calibre-Web. Its CVSS base score is 6.1 (Medium).

Operationally, ranked at the 47.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

A Cross-site Scripting (XSS) vulnerability exists in janeczku/calibre-web, specifically in the file `edit_books.js`. The vulnerability occurs when editing book properties, such as uploading a cover or a format. The affected code directly inserts user input into the DOM without proper…

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sanitization, allowing attackers to execute arbitrary JavaScript code. This can lead to various attacks, including stealing cookies. The issue is present in the code handling the `#btn-upload-cover` change event.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

janeczku
calibre-web
≤ 0.6.15

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References