Cyber Resilience

CVE-2021-3987

MediumPublic PoC

Published: 15 November 2024

Published
15 November 2024
Modified
19 November 2024
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0011 28.7th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3987 is a medium-severity Improper Access Control (CWE-284) vulnerability in Janeczku Calibre-Web. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 28.7th 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

An improper access control vulnerability exists in janeczku/calibre-web. The affected version allows users without public shelf permissions to create public shelves. The vulnerability is due to the `create_shelf` method in `shelf.py` not verifying if the user has the necessary permissions…

more

to create a public shelf. This issue can lead to unauthorized actions being performed by users.

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-284 CWE-862

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284 CWE-862

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284 CWE-862

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284 CWE-862

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284 CWE-862

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284 CWE-862

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

addresses: CWE-284 CWE-862

Requiring authorization and configuration controls for mobile device connections directly enforces access control and prevents unauthorized devices from reaching organizational systems.

addresses: CWE-284 CWE-862

Defining account types, requiring approvals for creation, specifying authorizations, monitoring usage, and reviewing accounts directly prevents improper access control by ensuring only authorized accounts exist and are used.

References