CVE-2023-51765

A flaw was found in some SMTP server configurations in Sendmail. This issue may allow a remote attacker to break out of the email message data to "smuggle" SMTP commands and send spoofed emails that pass SPF checks.

The Sendmail vulnerability allowing SMTP smuggling is deemed moderate due to its impact on SPF protection mechanisms and specific conditions for successful exploitation. SMTP smuggling involves manipulating the communication between mail servers to inject unauthorized messages. Exploiting this flaw involves a technique where remote attackers inject email messages with a spoofed MAIL FROM address. This manipulation allows them to bypass SPF protections because Sendmail supports the <LF>.<CR><LF> sequence, which some other popular email servers do not.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.