Vulnerability Monitor

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CVE-2025-53859


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.


Security Impact Summary

This vulnerability carries a LOW severity rating with a CVSS v3.1 score of 3.7, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited data confidentiality, for affected systems. Impacting 2 products from f5, from f5 organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2025, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2025-08-13T15:15:37.657

Last Modified

2025-11-04T22:16:27.033

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 3.7 (LOW)

Weaknesses
  • Type: Secondary
    CWE-125

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application f5 nginx_plus r30 Yes
Application f5 nginx_plus r31 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r34 Yes
Application f5 nginx_plus r34 Yes
Application f5 nginx_open_source < 1.29.1 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For f5's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.