What is CVE-2021-43430?

CVE-2021-43430 is a high-severity vulnerability in Bigantsoft Bigant Office Messenger 5, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2022-04-07.

How severe is CVE-2021-43430?

High severity. CVSS v3 base score is 8.8 out of 10.

Arbitrary file upload in Bigantsoft Bigant Office Messenger 5

CVE-2021-43430

An Access Control vulnerability exists in BigAntSoft BigAnt office messenger 5.6 via im_webserver, which could let a malicious user upload PHP Trojan files.

Vulnerability class: Unrestricted File Upload

Published 2022-04-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.011 (65.4th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 65.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Bigantsoft Bigant Office Messenger 5 — versions 5.6

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

github.com/Flash1201/bug/blob/main/bigant (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43430?: CVE-2021-43430 is a high-severity vulnerability in Bigantsoft Bigant Office Messenger 5, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2022-04-07.
How severe is CVE-2021-43430?: High severity. CVSS v3 base score is 8.8 out of 10.