CVE-2021-20745

Inkdrop versions prior to v5.3.1 allows an attacker to execute arbitrary OS commands on the system where it runs by loading a file or code snippet containing an invalid iframe into Inkdrop.

Published: 2021-06-28 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20745 is rated Moderate Risk (47.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.25%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-20745

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-29 0.42% 0.25% -0.17%
2 2025-11-21 0.28% 0.42% +0.14%
3 2025-11-18 — 0.28% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20745

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 10.0 [email protected]

Weakness enumeration for CVE-2021-20745

Affected software / configurations for CVE-2021-20745

Vendor Product Version Raw CPE
inkdrop inkdrop < 5.3.1 cpe:2.3:a:inkdrop:inkdrop:*:*:*:*:*:*:*:*

References for CVE-2021-20745

URL Tags
https://docs.inkdrop.app/releases/5.3.1 Release Notes Vendor Advisory
https://jvn.jp/en/jp/JVN29949691/index.html Third Party Advisory
https://www.inkdrop.app/ Product Vendor Advisory
cvelogic Threat Intelligence