Ubuntu: Security Advisory (USN-4424-1)

# SPDX-FileCopyrightText: 2020 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("1.3.6.1.4.1.25623.1.0.844499");
  script_cve_id("CVE-2020-11933", "CVE-2020-11934");
  script_tag(name:"creation_date", value:"2020-07-16 03:00:18 +0000 (Thu, 16 Jul 2020)");
  script_version("2024-02-02T05:06:07+0000");
  script_tag(name:"last_modification", value:"2024-02-02 05:06:07 +0000 (Fri, 02 Feb 2024)");
  script_tag(name:"cvss_base", value:"4.6");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-08-05 18:54:57 +0000 (Wed, 05 Aug 2020)");

  script_name("Ubuntu: Security Advisory (USN-4424-1)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 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(16\.04\ LTS|18\.04\ LTS|19\.10|20\.04\ LTS)");

  script_xref(name:"Advisory-ID", value:"USN-4424-1");
  script_xref(name:"URL", value:"https://ubuntu.com/security/notices/USN-4424-1");

  script_tag(name:"summary", value:"The remote host is missing an update for the 'snapd' package(s) announced via the USN-4424-1 advisory.");

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

  script_tag(name:"insight", value:"It was discovered that cloud-init as managed by snapd on Ubuntu Core 16 and
Ubuntu Core 18 devices ran on every boot without restrictions. A physical
attacker could exploit this to craft cloud-init user-data/meta-data via
external media to perform arbitrary changes on the device to bypass
intended security mechanisms such as full disk encryption. This issue did
not affect traditional Ubuntu systems. (CVE-2020-11933)

It was discovered that snapctl user-open allowed altering the XDG_DATA_DIRS
environment variable when calling the system xdg-open. A malicious snap
could exploit this to bypass intended access restrictions to control how
the host system xdg-open script opens the URL. This issue did not affect
Ubuntu Core systems. (CVE-2020-11934)");

  script_tag(name:"affected", value:"'snapd' package(s) on Ubuntu 16.04, Ubuntu 18.04, Ubuntu 19.10, Ubuntu 20.04.");

  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 == "UBUNTU16.04 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"snapd", ver:"2.45.1ubuntu0.2", rls:"UBUNTU16.04 LTS"))) {
    report += res;
  }

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

if(release == "UBUNTU18.04 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"snapd", ver:"2.45.1+18.04.2", rls:"UBUNTU18.04 LTS"))) {
    report += res;
  }

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

if(release == "UBUNTU19.10") {

  if(!isnull(res = isdpkgvuln(pkg:"snapd", ver:"2.45.1+19.10.2", rls:"UBUNTU19.10"))) {
    report += res;
  }

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

if(release == "UBUNTU20.04 LTS") {

  if(!isnull(res = isdpkgvuln(pkg:"snapd", ver:"2.45.1+20.04.2", rls:"UBUNTU20.04 LTS"))) {
    report += res;
  }

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

exit(0);