The remote host is affected by the vulnerability described in GLSA-200609-17 (OpenSSH: Denial of Service)
Tavis Ormandy of the Google Security Team discovered a Denial of Service vulnerability in the SSH protocol version 1 CRC compensation attack detector.
Impact :
A remote unauthenticated attacker may be able to trigger excessive CPU usage by sending a pathological SSH message, denying service to other legitimate users or processes.
Workaround :
The system administrator may disable SSH protocol version 1 in /etc/ssh/sshd_config.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Gentoo Linux Security Advisory GLSA 200609-17.
#
# The advisory text is Copyright (C) 2001-2015 Gentoo Foundation, Inc.
# and licensed under the Creative Commons - Attribution / Share Alike
# license. See http://creativecommons.org/licenses/by-sa/3.0/
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(22464);
script_version("1.16");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/06");
script_cve_id("CVE-2006-4924");
script_bugtraq_id(20216);
script_xref(name:"GLSA", value:"200609-17");
script_name(english:"GLSA-200609-17 : OpenSSH: Denial of Service");
script_summary(english:"Checks for updated package(s) in /var/db/pkg");
script_set_attribute(
attribute:"synopsis",
value:
"The remote Gentoo host is missing one or more security-related
patches."
);
script_set_attribute(
attribute:"description",
value:
"The remote host is affected by the vulnerability described in GLSA-200609-17
(OpenSSH: Denial of Service)
Tavis Ormandy of the Google Security Team discovered a Denial of
Service vulnerability in the SSH protocol version 1 CRC compensation
attack detector.
Impact :
A remote unauthenticated attacker may be able to trigger excessive CPU
usage by sending a pathological SSH message, denying service to other
legitimate users or processes.
Workaround :
The system administrator may disable SSH protocol version 1 in
/etc/ssh/sshd_config."
);
script_set_attribute(
attribute:"see_also",
value:"https://security.gentoo.org/glsa/200609-17"
);
script_set_attribute(
attribute:"solution",
value:
"All OpenSSH users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose '>=net-misc/openssh-4.3_p2-r5'"
);
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_cwe_id(399);
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:openssh");
script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux");
script_set_attribute(attribute:"patch_publication_date", value:"2006/09/27");
script_set_attribute(attribute:"plugin_publication_date", value:"2006/09/28");
script_set_attribute(attribute:"vuln_publication_date", value:"2006/09/25");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2006-2021 Tenable Network Security, Inc.");
script_family(english:"Gentoo Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/Gentoo/release", "Host/Gentoo/qpkg-list");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("qpkg.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Gentoo/release")) audit(AUDIT_OS_NOT, "Gentoo");
if (!get_kb_item("Host/Gentoo/qpkg-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (qpkg_check(package:"net-misc/openssh", unaffected:make_list("ge 4.3_p2-r5"), vulnerable:make_list("lt 4.3_p2-r5"))) flag++;
if (flag)
{
if (report_verbosity > 0) security_hole(port:0, extra:qpkg_report_get());
else security_hole(0);
exit(0);
}
else
{
tested = qpkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "OpenSSH");
}