A flaw was found in the way TLS 1.2 could use the MD5 hash function for signing ServerKeyExchange and Client Authentication packets during a TLS handshake. A man-in-the-middle attacker able to force a TLS connection to use the MD5 hash function could use this flaw to conduct collision attacks to impersonate a TLS server or an authenticated TLS client. (CVE-2015-7575)
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2016-645.
#
include("compat.inc");
if (description)
{
script_id(88657);
script_version("2.4");
script_cvs_date("Date: 2018/04/18 15:09:35");
script_cve_id("CVE-2015-7575");
script_xref(name:"ALAS", value:"2016-645");
script_xref(name:"RHSA", value:"2016:0007");
script_name(english:"Amazon Linux AMI : nss (ALAS-2016-645) (SLOTH)");
script_summary(english:"Checks rpm output for the updated packages");
script_set_attribute(
attribute:"synopsis",
value:"The remote Amazon Linux AMI host is missing a security update."
);
script_set_attribute(
attribute:"description",
value:
"A flaw was found in the way TLS 1.2 could use the MD5 hash function
for signing ServerKeyExchange and Client Authentication packets during
a TLS handshake. A man-in-the-middle attacker able to force a TLS
connection to use the MD5 hash function could use this flaw to conduct
collision attacks to impersonate a TLS server or an authenticated TLS
client. (CVE-2015-7575)"
);
script_set_attribute(
attribute:"see_also",
value:"https://alas.aws.amazon.com/ALAS-2016-645.html"
);
script_set_attribute(
attribute:"solution",
value:"Run 'yum update nss' to update your system."
);
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nss");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nss-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nss-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nss-pkcs11-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nss-sysinit");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:nss-tools");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
script_set_attribute(attribute:"patch_publication_date", value:"2016/02/09");
script_set_attribute(attribute:"in_the_news", value:"true");
script_set_attribute(attribute:"plugin_publication_date", value:"2016/02/10");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2016-2018 Tenable Network Security, Inc.");
script_family(english:"Amazon Linux Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "A")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (rpm_check(release:"ALA", reference:"nss-3.19.1-19.75.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"nss-debuginfo-3.19.1-19.75.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"nss-devel-3.19.1-19.75.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"nss-pkcs11-devel-3.19.1-19.75.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"nss-sysinit-3.19.1-19.75.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"nss-tools-3.19.1-19.75.amzn1")) flag++;
if (flag)
{
if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
else security_warning(0);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "nss / nss-debuginfo / nss-devel / nss-pkcs11-devel / nss-sysinit / etc");
}