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Fencer Vulns
medium 4.3

CVE-2023-33956 json

Parameter based Indirect Object Referencing leading to private file exposure in Kanboard

published 2023-06-05 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-38090

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

Kanboard is open source project management software that focuses on the Kanban methodology. Versions prior to 1.2.30 are subject to an Insecure direct object reference (IDOR) vulnerability present in the application's URL parameter. This vulnerability enables any user to read files uploaded by any other user, regardless of their privileges or restrictions. By Changing the file_id any user can render all the files where MimeType is image uploaded under **/files** directory regard less of uploaded by any user. This vulnerability poses a significant impact and severity to the application's security. By manipulating the URL parameter, an attacker can access sensitive files that should only be available to authorized users. This includes confidential documents or any other type of file stored within the application. The ability to read these files can lead to various detrimental consequences, such as unauthorized disclosure of sensitive information, privacy breaches, intellectual property theft, or exposure of trade secrets. Additionally, it could result in legal and regulatory implications, reputation damage, financial losses, and potential compromise of user trust. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

  • kanboard kanboard 1.2.30

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
22 mo ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/kanboard/kanboard/security/advisories/GHSA-r36m-44gg-wxg2 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

  • kanboard kanboard

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

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.