Ubuntu: Security Advisory (USN-612-9)

# SPDX-FileCopyrightText: 2009 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.840236");
  script_tag(name:"creation_date", value:"2009-03-23 09:59:50 +0000 (Mon, 23 Mar 2009)");
  script_version("2023-07-05T05:06:16+0000");
  script_tag(name:"last_modification", value:"2023-07-05 05:06:16 +0000 (Wed, 05 Jul 2023)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:N/A:N");

  script_name("Ubuntu: Security Advisory (USN-612-9)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2009 Greenbone AG");
  script_family("Ubuntu Local Security Checks");
  script_dependencies("gather-package-list.nasl");
  script_mandatory_keys("ssh/login/ubuntu_linux", "ssh/login/packages", re:"ssh/login/release=UBUNTU(6\.06\ LTS|7\.04|7\.10|8\.04\ LTS)");

  script_xref(name:"Advisory-ID", value:"USN-612-9");
  script_xref(name:"URL", value:"https://ubuntu.com/security/notices/USN-612-9");
  script_xref(name:"URL", value:"http://www.ubuntu.com/usn/usn-612-1");
  script_xref(name:"URL", value:"http://www.ubuntu.com/usn/usn-612-3");
  script_xref(name:"URL", value:"http://www.ubuntu.com/usn/usn-612-8");

  script_tag(name:"summary", value:"The remote host is missing an update for the 'openssl-blacklist' package(s) announced via the USN-612-9 advisory.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable package version is present on the target host.");

  script_tag(name:"insight", value:"USN-612-3 addressed a weakness in OpenSSL certificate and key
generation in OpenVPN by introducing openssl-blacklist to aid in
detecting vulnerable private keys. This update enhances the
openssl-vulnkey tool to check Certificate Signing Requests, accept
input from STDIN, and check moduli without a certificate.

It was also discovered that additional moduli are vulnerable if
generated with OpenSSL 0.9.8g or higher. While it is believed that
there are few of these vulnerable moduli in use, this update
includes updated RSA-1024 and RSA-2048 blocklists. RSA-512
blocklists are also included in the new openssl-blacklist-extra
package.

You can check for weak SSL/TLS certificates by installing
openssl-blacklist via your package manager, and using the
openssl-vulnkey command.

$ openssl-vulnkey /path/to/certificate_or_key
$ cat /path/to/certificate_or_key <pipe> openssl-vulnkey -

You can also check if a modulus is vulnerable by specifying the
modulus and number of bits.

$ openssl-vulnkey -b bits -m modulus

These commands can be used on public certificates, requests, and
private keys for any X.509 certificate, CSR, or RSA key, including
ones for web servers, mail servers, OpenVPN, and others. If in
doubt, destroy the certificate and key and generate new ones.
Please consult the documentation for your software when recreating
SSL/TLS certificates. Also, if certificates have been generated
for use on other systems, they must be found and replaced as well.

Original advisory details:
 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.");

  script_tag(name:"affected", value:"'openssl-blacklist' package(s) on Ubuntu 6.06, Ubuntu 7.04, Ubuntu 7.10, Ubuntu 8.04.");

  script_tag(name:"solution", value:"Please install the updated package(s).");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"package");

  exit(0);
}

include("revisions-lib.inc");
include("pkg-lib-deb.inc");

release = dpkg_get_ssh_release();
if(!release)
  exit(0);

res = "";
report = "";

if(release == "UBUNTU6.06 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist", ver:"0.3.3+0.4-0ubuntu0.6.06.1", rls:"UBUNTU6.06 LTS"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist-extra", ver:"0.3.3+0.4-0ubuntu0.6.06.1", rls:"UBUNTU6.06 LTS"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

if(release == "UBUNTU7.04") {

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist", ver:"0.3.3+0.4-0ubuntu0.7.04.1", rls:"UBUNTU7.04"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist-extra", ver:"0.3.3+0.4-0ubuntu0.7.04.1", rls:"UBUNTU7.04"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

if(release == "UBUNTU7.10") {

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist", ver:"0.3.3+0.4-0ubuntu0.7.10.1", rls:"UBUNTU7.10"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist-extra", ver:"0.3.3+0.4-0ubuntu0.7.10.1", rls:"UBUNTU7.10"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

if(release == "UBUNTU8.04 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist", ver:"0.3.3+0.4-0ubuntu0.8.04.1", rls:"UBUNTU8.04 LTS"))) {
    report += res;
  }

  if(!isnull(res = isdpkgvuln(pkg:"openssl-blacklist-extra", ver:"0.3.3+0.4-0ubuntu0.8.04.1", rls:"UBUNTU8.04 LTS"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

exit(0);