OpenSSL: ChaCha20-Poly1305 with long nonces (CVE-2019-1543) - Linux

# SPDX-FileCopyrightText: 2019 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

CPE = "cpe:/a:openssl:openssl";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.108610");
  script_version("2024-02-19T05:05:57+0000");
  script_cve_id("CVE-2019-1543");
  script_tag(name:"cvss_base", value:"5.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:P/I:P/A:N");
  script_tag(name:"last_modification", value:"2024-02-19 05:05:57 +0000 (Mon, 19 Feb 2024)");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-06-03 20:29:00 +0000 (Mon, 03 Jun 2019)");
  script_tag(name:"creation_date", value:"2019-07-03 06:06:21 +0000 (Wed, 03 Jul 2019)");
  script_name("OpenSSL: ChaCha20-Poly1305 with long nonces (CVE-2019-1543) - Linux");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2019 Greenbone AG");
  script_family("General");
  script_dependencies("gb_openssl_consolidation.nasl", "os_detection.nasl");
  script_mandatory_keys("openssl/detected", "Host/runs_unixoide");

  script_xref(name:"URL", value:"https://www.openssl.org/news/secadv/20190306.txt");
  script_xref(name:"URL", value:"https://seclists.org/bugtraq/2019/Jul/3");
  script_xref(name:"URL", value:"https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=ee22257b1418438ebaf54df98af4e24f494d1809");
  script_xref(name:"URL", value:"https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=f426625b6ae9a7831010750490a5f0ad689c5ba3");
  script_xref(name:"URL", value:"https://www.openssl.org/news/cl111.txt");
  script_xref(name:"URL", value:"https://www.openssl.org/news/cl110.txt");

  script_tag(name:"summary", value:"OpenSSL is prone to a vulnerability which allows a nonce reuse.");

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

  script_tag(name:"insight", value:"ChaCha20-Poly1305 is an AEAD cipher, and requires
  a unique nonce input for every encryption operation. RFC 7539 specifies that the
  nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce
  length and front pads the nonce with 0 bytes if it is less than 12 bytes. However
  it also incorrectly allows a nonce to be set of up to 16 bytes. In this case only
  the last 12 bytes are significant and any additional leading bytes are ignored.

  It is a requirement of using this cipher that nonce values are unique. Messages
  encrypted using a reused nonce value are susceptible to serious confidentiality
  and integrity attacks. If an application changes the default nonce length to be
  longer than 12 bytes and then makes a change to the leading bytes of the nonce
  expecting the new value to be a new unique nonce then such an application could
  inadvertently encrypt messages with a reused nonce.

  Additionally the ignored bytes in a long nonce are not covered by the integrity
  guarantee of this cipher. Any application that relies on the integrity of these
  ignored leading bytes of a long nonce may be further affected.

  Any OpenSSL internal use of this cipher, including in SSL/TLS, is safe because
  no such use sets such a long nonce value. However user applications that use
  this cipher directly and set a non-default nonce length to be longer than 12
  bytes may be vulnerable.");

  script_tag(name:"affected", value:"OpenSSL versions 1.1.1 up to and including 1.1.1b and
  1.1.0 up to and including 1.1.0j.

  This issue does not impact OpenSSL 1.0.2.");

  script_tag(name:"solution", value:"Upgrade OpenSSL to version 1.1.0k, 1.1.1c or later.
  See the references for more details.");

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

  exit(0);
}

include("host_details.inc");
include("version_func.inc");

if( isnull( port = get_app_port( cpe:CPE ) ) )
  exit( 0 );

if( ! infos = get_app_version_and_location( cpe:CPE, port:port, exit_no_version:TRUE ) )
  exit( 0 );

vers = infos["version"];
path = infos["location"];

if( version_in_range( version:vers, test_version:"1.1.0", test_version2:"1.1.0j" ) ) {
  report = report_fixed_ver( installed_version:vers, fixed_version:"1.1.0k", install_path:path );
  security_message( port:port, data:report );
  exit( 0 );
}

if( version_in_range( version:vers, test_version:"1.1.1", test_version2:"1.1.1b" ) ) {
  report = report_fixed_ver( installed_version:vers, fixed_version:"1.1.1c", install_path:path );
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );