CVE-2025-54336 (CVSS 9.8)

Description

In Plesk Obsidian 18.0.70, _isAdminPasswordValid uses an == comparison. Thus, if the correct password is "0e" followed by any digit string, then an attacker can login with any other string that evaluates to 0.0 (such as the 0e0 string). This occurs in admin/plib/LoginManager.php.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-697 CWE-697

References

Other References

https://blog.aziz.tn/2025/08/cve-2025-54336.html/ https://support.plesk.com/hc/en-us/articles/33785727869847-Vulnerability-CVE-2025-54336 https://www.plesk.com/blog/plesk-news-announcements/introducing-plesk-obsidian-18-0-70-anniversary-edition/

Frequently Asked Questions

What is CVE-2025-54336? +

In Plesk Obsidian 18.0.70, _isAdminPasswordValid uses an == comparison. Thus, if the correct password is "0e" followed by any digit string, then an attacker can login with any other string that evaluates to 0.0 (such as the 0e0 string). This occurs in admin/plib/LoginManager.php. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2025-54336? +

CVE-2025-54336 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

How do I check if I'm vulnerable to CVE-2025-54336? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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