kiwitcms vulnerable to stored XSS via unrestricted files upload

Description

Impact

Kiwi TCMS allows users to upload attachments to test plans, test cases, etc. Earlier versions of Kiwi TCMS had introduced upload validators in order to prevent potentially dangerous files from being uploaded, see GHSA-fwcf-753v-fgcj and Content-Security-Policy definition to prevent cross-site-scripting attacks, see GHSA-2wcr-87wf-cf9j.

The upload validation checks were not robust enough which left the possibility of an attacker to circumvent them and upload a potentially dangerous file. Exploting this flaw a combination of files could be uploaded so that they work together to circumvent the existing Content-Security-Policy and allow execution of arbitrary JavaScript in the browser.

Patches

  • File upload validation code has been improved
  • Kiwi TCMS will now force Content-Type: text/plain when serving uploaded files

Workarounds

1) Force the Content-Type header via a custom Django middleware, see ExtraHeadersMiddleware in https://github.com/kiwitcms/Kiwi/blob/master/tcms/core/middleware.py#L23 and/or
2) Force the Content-Type header via Nginx overrides, see location /uploads/ in https://github.com/kiwitcms/Kiwi/blob/master/etc/nginx.conf

References

Disclosed by Antonio Spataro and ek1ng. Additional credits to Ahmed Rabeaa Mosa.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2023-05-22 19:39:46 UTC
Updated
2023-11-07 05:05:31 UTC
GitHub reviewed
2023-05-22 19:39:46 UTC
NVD published
2023-05-27

EPSS Score

Score Percentile
0.93% 75.92%

CVSS Scores

Base score Version Severity Vector
5.4 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-434 Unrestricted Upload of File with Dangerous Type

Credits

  • antoniospataro (analyst)
  • mosaa404 (analyst)
  • ek1ng (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip kiwitcms < 12.3 12.3

References

cvelogic Threat Intelligence