Ubuntu 4.10 / 5.04 / 5.10 : gnupg vulnerability (USN-252-1)

2006-03-13T00:00:00
ID UBUNTU_USN-252-1.NASL
Type nessus
Reporter Tenable
Modified 2018-08-15T00:00:00

Description

Tavis Ormandy discovered a potential weakness in the signature verification of gnupg. gpgv and gpg --verify returned a successful exit code even if the checked file did not have any signature at all. The recommended way of checking the result is to evaluate the status messages, but some third-party applications might just check the exit code for determining whether or not a signature is valid. These applications could be tricked into erroneously reporting a valid signature.

Please note that this does not affect the Ubuntu package signature checks.

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 70103

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-252-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(21071);
  script_version("1.14");
  script_cvs_date("Date: 2018/08/15 16:35:43");

  script_cve_id("CVE-2006-0455");
  script_xref(name:"USN", value:"252-1");

  script_name(english:"Ubuntu 4.10 / 5.04 / 5.10 : gnupg vulnerability (USN-252-1)");
  script_summary(english:"Checks dpkg output for updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Ubuntu host is missing a security-related patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Tavis Ormandy discovered a potential weakness in the signature
verification of gnupg. gpgv and gpg --verify returned a successful
exit code even if the checked file did not have any signature at all.
The recommended way of checking the result is to evaluate the status
messages, but some third-party applications might just check the exit
code for determining whether or not a signature is valid. These
applications could be tricked into erroneously reporting a valid
signature.

Please note that this does not affect the Ubuntu package signature
checks.

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 gnupg package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnupg");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:4.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:5.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:5.10");

  script_set_attribute(attribute:"patch_publication_date", value:"2006/02/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2006/03/13");
  script_set_attribute(attribute:"vuln_publication_date", value:"2006/02/15");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2006-2018 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|5\.04|5\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 4.10 / 5.04 / 5.10", "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:"gnupg", pkgver:"1.2.4-4ubuntu2.2")) flag++;
if (ubuntu_check(osver:"5.04", pkgname:"gnupg", pkgver:"1.2.5-3ubuntu5.2")) flag++;
if (ubuntu_check(osver:"5.10", pkgname:"gnupg", pkgver:"1.4.1-1ubuntu1.1")) 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, "gnupg");
}