Scientific Linux Security Update : nss on SL6.x, SL7.x i386/x86_64 (Logjam)

2015-07-06T00:00:00
ID SL_20150625_NSS_ON_SL6_X.NASL
Type nessus
Reporter Tenable
Modified 2016-10-19T00:00:00

Description

A flaw was found in the way the TLS protocol composes the Diffie-Hellman (DH) key exchange. A man-in-the-middle attacker could use this flaw to force the use of weak 512 bit export-grade keys during the key exchange, allowing them do decrypt all traffic. (CVE-2015-4000)

Note: This update forces the TLS/SSL client implementation in NSS to reject DH key sizes below 768 bits, which prevents sessions to be downgraded to export-grade keys. Future updates may raise this limit to 1024 bits.

The nss and nss-util packages have been upgraded to upstream versions 3.19.1. The upgraded versions provide a number of bug fixes and enhancements over the previous versions.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text is (C) Scientific Linux.
#

include("compat.inc");

if (description)
{
  script_id(84539);
  script_version("$Revision: 2.6 $");
  script_cvs_date("$Date: 2016/10/19 14:25:12 $");

  script_cve_id("CVE-2015-4000");

  script_name(english:"Scientific Linux Security Update : nss on SL6.x, SL7.x i386/x86_64 (Logjam)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Scientific Linux host is missing one or more security
updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"A flaw was found in the way the TLS protocol composes the
Diffie-Hellman (DH) key exchange. A man-in-the-middle attacker could
use this flaw to force the use of weak 512 bit export-grade keys
during the key exchange, allowing them do decrypt all traffic.
(CVE-2015-4000)

Note: This update forces the TLS/SSL client implementation in NSS to
reject DH key sizes below 768 bits, which prevents sessions to be
downgraded to export-grade keys. Future updates may raise this limit
to 1024 bits.

The nss and nss-util packages have been upgraded to upstream versions
3.19.1. The upgraded versions provide a number of bug fixes and
enhancements over the previous versions."
  );
  # http://listserv.fnal.gov/scripts/wa.exe?A2=ind1506&L=scientific-linux-errata&F=&S=&P=14561
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?f9f162d1"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  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:N/I:L/A:N");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"x-cpe:/o:fermilab:scientific_linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2015/06/25");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/07/06");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2015-2016 Tenable Network Security, Inc.");
  script_family(english:"Scientific Linux Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/RedHat/release", "Host/RedHat/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/RedHat/release");
if (isnull(release) || "Scientific Linux " >!< release) audit(AUDIT_HOST_NOT, "running Scientific Linux");
if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if (cpu >!< "x86_64" && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Scientific Linux", cpu);


flag = 0;
if (rpm_check(release:"SL6", reference:"nss-3.19.1-3.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-debuginfo-3.19.1-3.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-devel-3.19.1-3.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-pkcs11-devel-3.19.1-3.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-sysinit-3.19.1-3.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-tools-3.19.1-3.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-util-3.19.1-1.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-util-debuginfo-3.19.1-1.el6_6")) flag++;
if (rpm_check(release:"SL6", reference:"nss-util-devel-3.19.1-1.el6_6")) flag++;

if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-3.19.1-3.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-debuginfo-3.19.1-3.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-devel-3.19.1-3.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-pkcs11-devel-3.19.1-3.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-sysinit-3.19.1-3.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-tools-3.19.1-3.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-util-3.19.1-1.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-util-debuginfo-3.19.1-1.el7_1")) flag++;
if (rpm_check(release:"SL7", cpu:"x86_64", reference:"nss-util-devel-3.19.1-1.el7_1")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");