Cyber Resilience

CVE-2021-25094

HighPublic PoC

Published: 25 April 2022

Published
25 April 2022
Modified
21 April 2025
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.9097 99.7th percentile
Risk Priority 71 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-25094 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Brandexponents Tatsu. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 0.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

The Tatsu WordPress plugin before 3.3.12 add_custom_font action can be used without prior authentication to upload a rogue zip file which is uncompressed under the WordPress's upload directory. By adding a PHP shell with a filename starting with a dot…

more

".", this can bypass extension control implemented in the plugin. Moreover, there is a race condition in the zip extraction process which makes the shell file live long enough on the filesystem to be callable by an attacker.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

brandexponents
tatsu
≤ 3.3.12

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-306

Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.

addresses: CWE-306

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

addresses: CWE-306

Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.

addresses: CWE-306

Guarantees critical functions are protected by mandatory invocation of the access control mechanism.

addresses: CWE-306

Auditing sessions makes it possible to detect access to critical functions without required authentication.

addresses: CWE-306

The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.

addresses: CWE-306

Certification assesses that critical functions have required authentication controls in place.

addresses: CWE-306

Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.

References