Ubuntu: Security Advisory (USN-6561-1)

# SPDX-FileCopyrightText: 2023 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("1.3.6.1.4.1.25623.1.1.12.2023.6561.1");
  script_cve_id("CVE-2023-48795");
  script_tag(name:"creation_date", value:"2023-12-20 04:08:43 +0000 (Wed, 20 Dec 2023)");
  script_version("2024-02-02T05:06:10+0000");
  script_tag(name:"last_modification", value:"2024-02-02 05:06:10 +0000 (Fri, 02 Feb 2024)");
  script_tag(name:"cvss_base", value:"5.4");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:H/Au:N/C:N/I:C/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2023-12-28 18:26:44 +0000 (Thu, 28 Dec 2023)");

  script_name("Ubuntu: Security Advisory (USN-6561-1)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2023 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(20\.04\ LTS|22\.04\ LTS|23\.04|23\.10)");

  script_xref(name:"Advisory-ID", value:"USN-6561-1");
  script_xref(name:"URL", value:"https://ubuntu.com/security/notices/USN-6561-1");

  script_tag(name:"summary", value:"The remote host is missing an update for the 'libssh' package(s) announced via the USN-6561-1 advisory.");

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

  script_tag(name:"insight", value:"Fabian Baumer, Marcus Brinkmann, Jorg Schwenk discovered that the SSH
protocol was vulnerable to a prefix truncation attack. If a remote attacker
was able to intercept SSH communications, extension negotiation messages
could be truncated, possibly leading to certain algorithms and features
being downgraded. This issue is known as the Terrapin attack. This update
adds protocol extensions to mitigate this issue.");

  script_tag(name:"affected", value:"'libssh' package(s) on Ubuntu 20.04, Ubuntu 22.04, Ubuntu 23.04, Ubuntu 23.10.");

  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 == "UBUNTU20.04 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"libssh-4", ver:"0.9.3-2ubuntu2.4", rls:"UBUNTU20.04 LTS"))) {
    report += res;
  }

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

if(release == "UBUNTU22.04 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"libssh-4", ver:"0.9.6-2ubuntu0.22.04.2", rls:"UBUNTU22.04 LTS"))) {
    report += res;
  }

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

if(release == "UBUNTU23.04") {

  if(!isnull(res = isdpkgvuln(pkg:"libssh-4", ver:"0.10.4-2ubuntu0.2", rls:"UBUNTU23.04"))) {
    report += res;
  }

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

if(release == "UBUNTU23.10") {

  if(!isnull(res = isdpkgvuln(pkg:"libssh-4", ver:"0.10.5-3ubuntu1.1", rls:"UBUNTU23.10"))) {
    report += res;
  }

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

exit(0);