Arbitrary file upload in Bitrix24

CVE-2023-1720

Lack of mime type response header in Bitrix24 22.0.300 allows authenticated remote attackers to execute arbitrary JavaScript code in the victim's browser, and possibly execute arbitrary PHP code on the server if the victim has administrator privilege, via uploading a crafted HTML file through /desktop_app/file.ajax.php?action=uploadfile.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (56.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-1720: held from 0.009 to 0.009.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-1720?
CVE-2023-1720 is a critical-severity vulnerability in Bitrix24, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.6/10. Published 2023-11-01.
How severe is CVE-2023-1720?
Critical severity. CVSS v3 base score is 9.6 out of 10.
Is CVE-2023-1720 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.