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nessusUbuntu Security Notice (C) 2004-2019 Canonical, Inc. / NASL script (C) 2006-2016 Tenable Network Security, Inc.UBUNTU_USN-34-1.NASL
HistoryJan 15, 2006 - 12:00 a.m.

Ubuntu 4.10 : openssh information leakage (USN-34-1)

2006-01-1500:00:00
Ubuntu Security Notice (C) 2004-2019 Canonical, Inc. / NASL script (C) 2006-2016 Tenable Network Security, Inc.
www.tenable.com
16

@Mediaservice.net discovered two information leaks in the OpenSSH server. When using password authentication, an attacker could test whether a login name exists by measuring the time between failed login attempts, i. e. the time after which the ‘password:’ prompt appears again.

A similar issue affects systems which do not allow root logins over ssh (‘PermitRootLogin no’). By measuring the time between login attempts an attacker could check whether a given root password is correct. This allowed determining weak root passwords using a brute force attack.

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

#%NASL_MIN_LEVEL 70300

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-34-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(20650);
  script_version("1.15");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/19");

  script_cve_id("CVE-2003-0190");
  script_xref(name:"USN", value:"34-1");

  script_name(english:"Ubuntu 4.10 : openssh information leakage (USN-34-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"@Mediaservice.net discovered two information leaks in the OpenSSH
server. When using password authentication, an attacker could test
whether a login name exists by measuring the time between failed login
attempts, i. e. the time after which the 'password:' prompt appears
again.

A similar issue affects systems which do not allow root logins over
ssh ('PermitRootLogin no'). By measuring the time between login
attempts an attacker could check whether a given root password is
correct. This allowed determining weak root passwords using a brute
force attack.

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues."
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:openssh-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ssh");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ssh-askpass-gnome");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:4.10");

  script_set_attribute(attribute:"patch_publication_date", value:"2004/11/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2006/01/15");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2004-2019 Canonical, Inc. / NASL script (C) 2006-2016 Tenable Network Security, Inc.");
  script_family(english:"Ubuntu Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! ereg(pattern:"^(4\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 4.10", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);

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

flag = 0;

if (ubuntu_check(osver:"4.10", pkgname:"openssh-client", pkgver:"3.8.1p1-11ubuntu3.1")) flag++;
if (ubuntu_check(osver:"4.10", pkgname:"openssh-server", pkgver:"3.8.1p1-11ubuntu3.1")) flag++;
if (ubuntu_check(osver:"4.10", pkgname:"ssh", pkgver:"3.8.1p1-11ubuntu3.1")) flag++;
if (ubuntu_check(osver:"4.10", pkgname:"ssh-askpass-gnome", pkgver:"3.8.1p1-11ubuntu3.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "openssh-client / openssh-server / ssh / ssh-askpass-gnome");
}
VendorProductVersionCPE
canonicalubuntu_linuxopenssh-clientp-cpe:/a:canonical:ubuntu_linux:openssh-client
canonicalubuntu_linuxopenssh-serverp-cpe:/a:canonical:ubuntu_linux:openssh-server
canonicalubuntu_linuxsshp-cpe:/a:canonical:ubuntu_linux:ssh
canonicalubuntu_linuxssh-askpass-gnomep-cpe:/a:canonical:ubuntu_linux:ssh-askpass-gnome
canonicalubuntu_linux4.10cpe:/o:canonical:ubuntu_linux:4.10