What is CVE-2020-18121?

CVE-2020-18121 is a high-severity vulnerability in Indexhibit, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 8.8/10. Published 2021-08-30.

How severe is CVE-2020-18121?

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

Vulnerability in Indexhibit

CVE-2020-18121

A configuration issue in Indexhibit 2.1.5 allows authenticated attackers to modify .php files, leading to getshell.

Published 2021-08-30 · 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: 0.010 (60.4th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 60.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Indexhibit — versions 2.1.5

Weakness classification (CWE)

CWE-732 — Incorrect Permission Assignment for Critical Resource

References

github.com/Indexhibit/indexhibit/issues/17 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2020-18121?: CVE-2020-18121 is a high-severity vulnerability in Indexhibit, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 8.8/10. Published 2021-08-30.
How severe is CVE-2020-18121?: High severity. CVSS v3 base score is 8.8 out of 10.