CVE coverage
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CVE-2023-51764
CVSS 5.3
6 detections found
Postfix through 3.8.5 allows SMTP smuggling unless configured with smtpd_data_restrictions=reject_unauth_pipelining and smtpd_discard_ehlo_keywords=chunking (or certain other options that exist in recent versions). Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Postfix supports <LF>.<CR><LF> but some other popular e-mail servers do not. To prevent attack variants (by always disallowing <LF> without <CR>), a different solution is required, such as the smtpd_forbid_bare_newline=yes option with a Postfix minimum version of 3.5.23, 3.6.13, 3.7.9, 3.8.4, or 3.9.
Detection rules
| Source | Rule | Status | Updated |
|---|---|---|---|
| suricata | ET EXPLOIT Inbound Smuggling Message from SMTP Smuggling Tool M1 | rev 2 | 2024-01-31 |
| suricata | ET EXPLOIT Inbound Smuggling Message from SMTP Smuggling Tool M2 | rev 2 | 2024-01-31 |
| suricata | ET EXPLOIT Inbound Setup Message from SMTP Smuggling Tool | rev 1 | 2024-01-05 |
| snort | ET EXPLOIT Inbound Setup Message from SMTP Smuggling Tool | rev 1 | 2024-01-05 |
| snort | ET EXPLOIT Inbound Smuggling Message from SMTP Smuggling Tool M1 | rev 1 | 2024-01-05 |
| snort | ET EXPLOIT Inbound Smuggling Message from SMTP Smuggling Tool M2 | rev 1 | 2024-01-05 |