Arbitrary file upload in 3cx Live Chat

CVE-2019-11185

The WP Live Chat Support Pro plugin through 8.0.26 for WordPress contains an arbitrary file upload vulnerability. This results from an incomplete patch for CVE-2018-12426. Arbitrary file upload is achieved by using a non-blacklisted executable file extension in conjunction with a whitelisted file extension, and prepending "magic bytes" to the payload to pass MIME checks. Specifically, an unauthenticated remote user submits a crafted file upload POST request to the REST api remote_upload endpoint. The file contains data that will fool the plugin's MIME check into classifying it as an image (which is a whitelisted file extension) and finally a trailing .phtml file extension.

Vulnerability class: Unrestricted File Upload

EPSS: 0.043 (90.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-11185?
CVE-2019-11185 is a critical-severity vulnerability in 3cx Live Chat, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2019-06-03.
How severe is CVE-2019-11185?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2019-11185 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.