CVE-2021-3987 json
Improper Access Control in janeczku/calibre-web
published 2024-11-15 23 mo ago modified 2026-07-07 4 mo ago also GHSA-fj5v-w2jp-wqvj , PYSEC-2026-1229 , EUVD-2024-3244
- cvss
- 5.4
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 28%
- public exploits
- 0
- none known
Summary
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 to create a public shelf. This issue can lead to unauthorized actions being performed by users.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- huntr.com https://huntr.com/bounties/29fcc091-87b6-43bc-ab4b-3c0bec3f71df referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 5.4 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| NVD | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| GitHub | 3.0 | 5.4 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
| OSV | 3.0 | 5.4 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | calibreweb | <0.6.15 |
0.6.15 |
Affected products
- janeczku janeczku/calibre-web
- calibre-web_project calibre-web
Classification
References
-
github.com
/janeczku/calibre-web/commit/bcdc97641447965af486964537f3821f47b28874
web, patch
-
huntr.com
/bounties/29fcc091-87b6-43bc-ab4b-3c0bec3f71df
web, exploit
-
nvd.nist.gov
/vuln/detail/CVE-2021-3987
advisory
-
github.com
/janeczku/calibre-web
package
-
pypi.org
/project/calibreweb
package
-
github.com
/advisories/GHSA-fj5v-w2jp-wqvj
advisory
Sources
- CVE List CVE-2021-3987
- GitHub Advisory GHSA-fj5v-w2jp-wqvj
- NVD CVE-2021-3987
- OSV PYSEC-2026-1229
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.