OpenBSD OpenSSH <= 9.6 Authentication Bypass Vulnerability

# SPDX-FileCopyrightText: 2024 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("1.3.6.1.4.1.25623.1.0.114398");
  script_version("2025-09-24T05:39:03+0000");
  script_tag(name:"last_modification", value:"2025-09-24 05:39:03 +0000 (Wed, 24 Sep 2025)");
  script_tag(name:"creation_date", value:"2024-02-29 08:02:29 +0000 (Thu, 29 Feb 2024)");
  script_tag(name:"cvss_base", value:"6.0");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:S/C:C/I:C/A:C");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2024-01-04 19:18:14 +0000 (Thu, 04 Jan 2024)");

  script_cve_id("CVE-2023-51767");

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

  script_tag(name:"solution_type", value:"WillNotFix");

  script_name("OpenBSD OpenSSH <= 9.6 Authentication Bypass Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2024 Greenbone AG");
  script_family("General");

  script_tag(name:"summary", value:"OpenBSD OpenSSH is prone to an authentication bypass
  vulnerability.

  Note: This VT has been deprecated and is therefore no longer functional. Please see the solution
  tag for more information.");

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

  script_tag(name:"insight", value:"When common types of DRAM are used, OpenSSH might allow row
  hammer attacks (for authentication bypass) because the integer value of authenticated in
  mm_answer_authpassword does not resist flips of a single bit.

  NOTE: this is applicable to a certain threat model of attacker-victim co-location in which the
  attacker has user privileges.");

  script_tag(name:"affected", value:"OpenBSD OpenSSH version 9.6 and prior.");

  script_tag(name:"solution", value:"No solution is required.

  Vendor statement: This attack was not demonstrated against stock OpenSSH, but instead against a
  modified sshd that had extra synchronisation added to make the attack easier.

  Nobody has demonstrated this attack against a configuration remotely approximating real-world
  conditions. We consider rowhammer mitigation to the job of the platform, not userspace
  software.");

  script_xref(name:"URL", value:"https://bugzilla.mindrot.org/show_bug.cgi?id=3656#c1");
  script_xref(name:"URL", value:"https://www.openwall.com/lists/oss-security/2025/09/22/1");
  script_xref(name:"URL", value:"https://access.redhat.com/security/cve/CVE-2023-51767");
  script_xref(name:"URL", value:"https://bugzilla.redhat.com/show_bug.cgi?id=2255850");
  script_xref(name:"URL", value:"https://arxiv.org/abs/2309.02545");
  script_xref(name:"URL", value:"https://www.openwall.com/lists/oss-security/2023/12/21/9");

  script_tag(name:"deprecated", value:TRUE);

  exit(0);
}

exit(66);