5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.1 Medium
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
65.3%
Postfix is prone to a SMTP smuggling vulnerability.
# SPDX-FileCopyrightText: 2024 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only
CPE = "cpe:/a:postfix:postfix";
if(description)
{
script_oid("1.3.6.1.4.1.25623.1.0.114255");
script_version("2024-01-12T05:05:56+0000");
script_tag(name:"last_modification", value:"2024-01-12 05:05:56 +0000 (Fri, 12 Jan 2024)");
script_tag(name:"creation_date", value:"2024-01-10 10:31:13 +0000 (Wed, 10 Jan 2024)");
script_tag(name:"cvss_base", value:"5.0");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:P/A:N");
script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N");
script_tag(name:"severity_origin", value:"NVD");
script_tag(name:"severity_date", value:"2024-01-05 16:19:00 +0000 (Fri, 05 Jan 2024)");
script_cve_id("CVE-2023-51764");
# nb: General availability of backports on major Linux distros but also only affected in specific
# configurations.
script_tag(name:"qod_type", value:"remote_banner_unreliable");
script_tag(name:"solution_type", value:"VendorFix");
script_name("Postfix SMTP Smuggling Vulnerability (Dec 2023)");
script_category(ACT_GATHER_INFO);
script_copyright("Copyright (C) 2024 Greenbone AG");
script_family("SMTP problems");
script_dependencies("sw_postfix_smtp_detect.nasl");
script_mandatory_keys("postfix/smtp/detected");
script_tag(name:"summary", value:"Postfix is prone to a SMTP smuggling vulnerability.");
script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");
script_tag(name:"insight", value:"Postfix 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: 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.");
script_tag(name:"affected", value:"Postfix versions through 3.8.4.");
script_tag(name:"solution", value:"Update to version 3.5.23, 3.6.13, 3.7.9, 3.8.4, 3.9 or later
and set the option mentioned by the vendor within the Postfix configuration.");
script_xref(name:"URL", value:"https://www.postfix.org/smtp-smuggling.html");
script_xref(name:"URL", value:"https://www.postfix.org/false-smuggling-claims.html");
script_xref(name:"URL", value:"https://www.postfix.org/announcements/postfix-3.8.4.html");
script_xref(name:"URL", value:"https://www.postfix.org/announcements/postfix-3.7.9.html");
script_xref(name:"URL", value:"https://www.postfix.org/announcements/postfix-3.6.13.html");
script_xref(name:"URL", value:"https://www.postfix.org/announcements/postfix-3.5.23.html");
script_xref(name:"URL", value:"https://www.mail-archive.com/[email protected]/msg100901.html");
script_xref(name:"URL", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2255563");
script_xref(name:"URL", value:"https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/");
script_xref(name:"URL", value:"https://www.openwall.com/lists/oss-security/2023/12/21/6");
script_xref(name:"URL", value:"https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html");
exit(0);
}
include("host_details.inc");
include("version_func.inc");
if (!port = get_app_port(cpe: CPE))
exit(0);
if (!version = get_app_version(cpe: CPE, port: port))
exit(0);
if (version_is_less(version: version, test_version: "3.5.23")) {
report = report_fixed_ver(installed_version: version, fixed_version: "3.5.23");
security_message(port: port, data: report);
exit(0);
}
if (version_in_range_exclusive(version: version, test_version_lo: "3.6", test_version_up: "3.6.13")) {
report = report_fixed_ver(installed_version: version, fixed_version: "3.6.13");
security_message(port: port, data: report);
exit(0);
}
if (version_in_range_exclusive(version: version, test_version_lo: "3.7", test_version_up: "3.7.9")) {
report = report_fixed_ver(installed_version: version, fixed_version: "3.7.9");
security_message(port: port, data: report);
exit(0);
}
if (version_in_range_exclusive(version: version, test_version_lo: "3.8", test_version_up: "3.8.4")) {
report = report_fixed_ver(installed_version: version, fixed_version: "3.8.4");
security_message(port: port, data: report);
exit(0);
}
exit(99);
bugzilla.redhat.com/show_bug.cgi?id=2255563
fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html
sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/
www.mail-archive.com/[email protected]/msg100901.html
www.openwall.com/lists/oss-security/2023/12/21/6
www.postfix.org/announcements/postfix-3.5.23.html
www.postfix.org/announcements/postfix-3.6.13.html
www.postfix.org/announcements/postfix-3.7.9.html
www.postfix.org/announcements/postfix-3.8.4.html
www.postfix.org/false-smuggling-claims.html
www.postfix.org/smtp-smuggling.html
5.3 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.1 Medium
AI Score
Confidence
High
0.003 Low
EPSS
Percentile
65.3%