Vulnerabilities > CVE-2008-2285 - Cryptographic Issues vulnerability in Ubuntu Linux 7.04/7.10/8.04

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
NONE
network
low complexity
ubuntu
CWE-310
nessus

Summary

The ssh-vulnkey tool on Ubuntu Linux 7.04, 7.10, and 8.04 LTS does not recognize authorized_keys lines that contain options, which makes it easier for remote attackers to exploit CVE-2008-0166 by guessing a key that was not identified by this tool.

Vulnerable Configurations

Part Description Count
Application
Ubuntu
3

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Signature Spoofing by Key Recreation
    An attacker obtains an authoritative or reputable signer's private signature key by exploiting a cryptographic weakness in the signature algorithm or pseudorandom number generation and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.

Nessus

NASL familyUbuntu Local Security Checks
NASL idUBUNTU_USN-612-5.NASL
descriptionMatt Zimmerman discovered that entries in ~/.ssh/authorized_keys with options (such as
last seen2020-06-01
modified2020-06-02
plugin id32359
published2008-05-16
reporterUbuntu Security Notice (C) 2008-2019 Canonical, Inc. / NASL script (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/32359
titleUbuntu 7.04 / 7.10 / 8.04 LTS : openssh update (USN-612-5)
code
#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-612-5. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(32359);
  script_version("1.15");
  script_cvs_date("Date: 2019/08/02 13:33:02");

  script_cve_id("CVE-2008-0166", "CVE-2008-2285");
  script_bugtraq_id(29179);
  script_xref(name:"USN", value:"612-5");

  script_name(english:"Ubuntu 7.04 / 7.10 / 8.04 LTS : openssh update (USN-612-5)");
  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:
"Matt Zimmerman discovered that entries in ~/.ssh/authorized_keys with
options (such as 'no-port-forwarding' or forced commands) were ignored
by the new ssh-vulnkey tool introduced in OpenSSH (see USN-612-2).
This could cause some compromised keys not to be listed in
ssh-vulnkey's output.

This update also adds more information to ssh-vulnkey's manual page.

A weakness has been discovered in the random number generator used by
OpenSSL on Debian and Ubuntu systems. As a result of this weakness,
certain encryption keys are much more common than they should be, such
that an attacker could guess the key through a brute-force attack
given minimal knowledge of the system. This particularly affects the
use of encryption keys in OpenSSH, OpenVPN and SSL certificates.

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:"see_also",
    value:"https://usn.ubuntu.com/612-5/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");
  script_cwe_id(310);

  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-client-udeb");
  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:"p-cpe:/a:canonical:ubuntu_linux:ssh-krb5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:7.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:7.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:8.04:-:lts");

  script_set_attribute(attribute:"patch_publication_date", value:"2008/05/14");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/05/16");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2008-2019 Canonical, Inc. / NASL script (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
  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:"^(7\.04|7\.10|8\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 7.04 / 7.10 / 8.04", "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:"7.04", pkgname:"openssh-client", pkgver:"1:4.3p2-8ubuntu1.4")) flag++;
if (ubuntu_check(osver:"7.04", pkgname:"openssh-client-udeb", pkgver:"1:4.3p2-8ubuntu1.4")) flag++;
if (ubuntu_check(osver:"7.04", pkgname:"openssh-server", pkgver:"4.3p2-8ubuntu1.4")) flag++;
if (ubuntu_check(osver:"7.04", pkgname:"ssh", pkgver:"4.3p2-8ubuntu1.4")) flag++;
if (ubuntu_check(osver:"7.04", pkgname:"ssh-askpass-gnome", pkgver:"4.3p2-8ubuntu1.4")) flag++;
if (ubuntu_check(osver:"7.04", pkgname:"ssh-krb5", pkgver:"4.3p2-8ubuntu1.4")) flag++;
if (ubuntu_check(osver:"7.10", pkgname:"openssh-client", pkgver:"1:4.6p1-5ubuntu0.5")) flag++;
if (ubuntu_check(osver:"7.10", pkgname:"openssh-client-udeb", pkgver:"1:4.6p1-5ubuntu0.5")) flag++;
if (ubuntu_check(osver:"7.10", pkgname:"openssh-server", pkgver:"4.6p1-5ubuntu0.5")) flag++;
if (ubuntu_check(osver:"7.10", pkgname:"ssh", pkgver:"4.6p1-5ubuntu0.5")) flag++;
if (ubuntu_check(osver:"7.10", pkgname:"ssh-askpass-gnome", pkgver:"4.6p1-5ubuntu0.5")) flag++;
if (ubuntu_check(osver:"7.10", pkgname:"ssh-krb5", pkgver:"4.6p1-5ubuntu0.5")) flag++;
if (ubuntu_check(osver:"8.04", pkgname:"openssh-client", pkgver:"1:4.7p1-8ubuntu1.2")) flag++;
if (ubuntu_check(osver:"8.04", pkgname:"openssh-client-udeb", pkgver:"1:4.7p1-8ubuntu1.2")) flag++;
if (ubuntu_check(osver:"8.04", pkgname:"openssh-server", pkgver:"4.7p1-8ubuntu1.2")) flag++;
if (ubuntu_check(osver:"8.04", pkgname:"ssh", pkgver:"4.7p1-8ubuntu1.2")) flag++;
if (ubuntu_check(osver:"8.04", pkgname:"ssh-askpass-gnome", pkgver:"4.7p1-8ubuntu1.2")) flag++;
if (ubuntu_check(osver:"8.04", pkgname:"ssh-krb5", pkgver:"4.7p1-8ubuntu1.2")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    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-client-udeb / openssh-server / ssh / etc");
}