CVE-2023-51766

Summary

CVE-2023-51766 is a vulnerability affecting Exim email servers before version 4.97.1. It enables SMTP smuggling in specific PIPELINING/CHUNKING configurations. Attackers can take advantage of this issue by injecting e-mail messages with spoofed MAIL FROM addresses. This bypasses SPF protection mechanisms, as Exim accepts <LF>.<CR><LF> line endings while many other popular e-mail servers do not. This vulnerability can potentially lead to email spoofing and unauthorized email delivery. To mitigate this risk, it is recommended to update to the latest version of Exim or implement additional email security measures.

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