Debian DSA-2869-1 : gnutls26 - incorrect certificate verification

2014-03-04T00:00:00
ID DEBIAN_DSA-2869.NASL
Type nessus
Reporter Tenable
Modified 2015-07-14T00:00:00

Description

Nikos Mavrogiannopoulos of Red Hat discovered an X.509 certificate verification issue in GnuTLS, an SSL/TLS library. A certificate validation could be reported sucessfully even in cases were an error would prevent all verification steps to be performed.

An attacker doing a man-in-the-middle of a TLS connection could use this vulnerability to present a carefully crafted certificate that would be accepted by GnuTLS as valid even if not signed by one of the trusted authorities.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-2869. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(72782);
  script_version("$Revision: 1.5 $");
  script_cvs_date("$Date: 2015/07/14 13:43:55 $");

  script_cve_id("CVE-2014-0092");
  script_bugtraq_id(65919);
  script_osvdb_id(103933);
  script_xref(name:"DSA", value:"2869");

  script_name(english:"Debian DSA-2869-1 : gnutls26 - incorrect certificate verification");
  script_summary(english:"Checks dpkg output for the updated package");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Nikos Mavrogiannopoulos of Red Hat discovered an X.509 certificate
verification issue in GnuTLS, an SSL/TLS library. A certificate
validation could be reported sucessfully even in cases were an error
would prevent all verification steps to be performed.

An attacker doing a man-in-the-middle of a TLS connection could use
this vulnerability to present a carefully crafted certificate that
would be accepted by GnuTLS as valid even if not signed by one of the
trusted authorities."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/squeeze/gnutls26"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/wheezy/gnutls26"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.debian.org/security/2014/dsa-2869"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the gnutls26 packages.

For the oldstable distribution (squeeze), this problem has been fixed
in version 2.8.6-1+squeeze3.

For the stable distribution (wheezy), this problem has been fixed in
version 2.12.20-8+deb7u1."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:ND/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:gnutls26");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:6.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:7.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2014/03/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/03/04");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2014-2015 Tenable Network Security, Inc.");
  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:"6.0", prefix:"gnutls-bin", reference:"2.8.6-1+squeeze3")) flag++;
if (deb_check(release:"6.0", prefix:"gnutls-doc", reference:"2.8.6-1+squeeze3")) flag++;
if (deb_check(release:"6.0", prefix:"guile-gnutls", reference:"2.8.6-1+squeeze3")) flag++;
if (deb_check(release:"6.0", prefix:"libgnutls-dev", reference:"2.8.6-1+squeeze3")) flag++;
if (deb_check(release:"6.0", prefix:"libgnutls26", reference:"2.8.6-1+squeeze3")) flag++;
if (deb_check(release:"6.0", prefix:"libgnutls26-dbg", reference:"2.8.6-1+squeeze3")) flag++;
if (deb_check(release:"7.0", prefix:"gnutls-bin", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"gnutls26-doc", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"guile-gnutls", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"libgnutls-dev", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"libgnutls-openssl27", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"libgnutls26", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"libgnutls26-dbg", reference:"2.12.20-8+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"libgnutlsxx27", reference:"2.12.20-8+deb7u1")) 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");