Stealthier phishing attacks possible with new SMTP smuggling technique>
SC Magazine –
A new Simple Mail Transfer Protocol (SMTP) smuggling technique could enable threat actors to conduct stealthier targeted phishing attacks, as reported by The Hacker News.
Vulnerable Microsoft, GMX, and Cisco SMTP servers globally may have inconsistencies in end-of-data sequence management that could be exploited, allowing arbitrary SMTP command smuggling and the delivery of spoofed emails with fraudulent sender addresses without detection by common email authentication protections.
A report from SEC Consult highlighted these concerns, also pointing out vulnerabilities in Sendmail’s and Postfix’s SMTP implementations.
While Microsoft and GMX have addressed the issue, Cisco indicated that the problem was a feature that did not require fixing.
As a result, Cisco Secure Email instances in default configurations remain susceptible to inbound SMTP smuggling.
To address this issue, users are encouraged by SEC Consult to activate “Allow” in their settings to mitigate the risk of fraudulent emails bypassing DMARC checks.
Link: https://www.scmagazine.com/brief/stealthier-phishing-attacks-possible-with-new-smtp-smuggling-technique