NGINX ngx_mail_smtp_module vulnerability_CVE-2025-53859

3.7 / 10

LOW

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

Description

NGINX Open Source and NGINX Plus have a vulnerability in the ngx_mail_smtp_module that might allow an unauthenticated attacker to over-read NGINX SMTP authentication process memory; as a result, the server side may leak arbitrary bytes sent in a request to the authentication server. This issue happens during the NGINX SMTP authentication process and requires the attacker to make preparations against the target system to extract the leaked data. The issue affects NGINX only if (1) it is built with the ngx_mail_smtp_module, (2) the smtp_auth directive is configured with method "none," and (3) the authentication server returns the "Auth-Wait" response header.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Basic Information

ID CVE-2025-53859

Source f5

Published Aug 13, 2025 at 14:46

Modified Aug 13, 2025 at 15:14

Affected Product

Vendor F5

Product NGINX Plus

Version R35

Affected Versions F5 NGINX Plus R34
F5 NGINX Plus R33
F5 NGINX Plus R32
F5 NGINX Plus R31
F5 NGINX Plus R30
F5 NGINX Open Source 0.7

CWE Classification

CWE-125

References

my.f5.com /manage/s/article/K000152786

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