Debian DLA-1474-1 : openssh security update

2018-08-22T00:00:00
ID DEBIAN_DLA-1474.NASL
Type nessus
Reporter Tenable
Modified 2018-11-01T00:00:00

Description

It was discovered that there was a user enumeration vulnerability in OpenSSH. A remote attacker couldtest whether a certain user exists on a target server.

For Debian 8 'Jessie', this issue has been fixed in openssh version 1:6.7p1-5+deb8u5.

We recommend that you upgrade your openssh packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1474-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(112050);
  script_version("1.3");
  script_cvs_date("Date: 2018/11/01  9:58:38");

  script_cve_id("CVE-2018-15473");

  script_name(english:"Debian DLA-1474-1 : openssh security update");
  script_summary(english:"Checks dpkg output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that there was a user enumeration vulnerability in
OpenSSH. A remote attacker couldtest whether a certain user exists on
a target server.

For Debian 8 'Jessie', this issue has been fixed in openssh version
1:6.7p1-5+deb8u5.

We recommend that you upgrade your openssh packages.

NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA security advisory. Tenable has attempted
to automatically clean and format it as much as possible without
introducing additional issues."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://lists.debian.org/debian-lts-announce/2018/08/msg00022.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/jessie/openssh"
  );
  script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:'CANVAS');

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:openssh-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:openssh-client-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:openssh-server-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:openssh-sftp-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ssh-askpass-gnome");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ssh-krb5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/08/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/22");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Debian Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("debian_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (deb_check(release:"8.0", prefix:"openssh-client", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"openssh-client-udeb", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"openssh-server", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"openssh-server-udeb", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"openssh-sftp-server", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"ssh", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"ssh-askpass-gnome", reference:"1:6.7p1-5+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"ssh-krb5", reference:"1:6.7p1-5+deb8u5")) flag++;

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