CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
82.6%
The remote Debian 10 / 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-4974 advisory.
Nextcloud Desktop Client before 3.3.1 is vulnerable to improper certificate validation due to lack of SSL certificate verification when using the Register with a Provider flow. (CVE-2021-22895)
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint.
In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.
(CVE-2021-32728)
Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dsa-4974. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(153485);
script_version("1.4");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/30");
script_cve_id("CVE-2021-22895", "CVE-2021-32728");
script_name(english:"Debian DSA-4974-1 : nextcloud-desktop - security update");
script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
script_set_attribute(attribute:"description", value:
"The remote Debian 10 / 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dsa-4974 advisory.
- Nextcloud Desktop Client before 3.3.1 is vulnerable to improper certificate validation due to lack of SSL
certificate verification when using the Register with a Provider flow. (CVE-2021-22895)
- The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients
using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint.
In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to
previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the
data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is
fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.
(CVE-2021-32728)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=989846");
# https://security-tracker.debian.org/tracker/source-package/nextcloud-desktop
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1c0ae60e");
script_set_attribute(attribute:"see_also", value:"https://www.debian.org/security/2021/dsa-4974");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-22895");
script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-32728");
script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/buster/nextcloud-desktop");
script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/bullseye/nextcloud-desktop");
script_set_attribute(attribute:"solution", value:
"Upgrade the nextcloud-desktop packages.
For the stable distribution (bullseye), these problems have been fixed in version 3.1.1-2+deb11u1.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-22895");
script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2021-32728");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2021/06/11");
script_set_attribute(attribute:"patch_publication_date", value:"2021/09/19");
script_set_attribute(attribute:"plugin_publication_date", value:"2021/09/19");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:caja-nextcloud");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:dolphin-nextcloud");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnextcloudsync-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libnextcloudsync0");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nautilus-nextcloud");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nemo-nextcloud");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nextcloud-desktop");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nextcloud-desktop-cmd");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nextcloud-desktop-common");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nextcloud-desktop-doc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:nextcloud-desktop-l10n");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:10.0");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Debian Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
exit(0);
}
include('audit.inc');
include('debian_package.inc');
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
var release = get_kb_item('Host/Debian/release');
if ( isnull(release) ) audit(AUDIT_OS_NOT, 'Debian');
var release = chomp(release);
if (! preg(pattern:"^(10)\.[0-9]+|^(11)\.[0-9]+", string:release)) audit(AUDIT_OS_NOT, 'Debian 10.0 / 11.0', 'Debian ' + release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);
var pkgs = [
{'release': '10.0', 'prefix': 'caja-nextcloud', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'dolphin-nextcloud', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'libnextcloudsync-dev', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'libnextcloudsync0', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nautilus-nextcloud', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nemo-nextcloud', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nextcloud-desktop', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nextcloud-desktop-cmd', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nextcloud-desktop-common', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nextcloud-desktop-doc', 'reference': '2.5.1-3+deb10u2'},
{'release': '10.0', 'prefix': 'nextcloud-desktop-l10n', 'reference': '2.5.1-3+deb10u2'},
{'release': '11.0', 'prefix': 'caja-nextcloud', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'dolphin-nextcloud', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'libnextcloudsync-dev', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'libnextcloudsync0', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nautilus-nextcloud', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nemo-nextcloud', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nextcloud-desktop', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nextcloud-desktop-cmd', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nextcloud-desktop-common', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nextcloud-desktop-doc', 'reference': '3.1.1-2+deb11u1'},
{'release': '11.0', 'prefix': 'nextcloud-desktop-l10n', 'reference': '3.1.1-2+deb11u1'}
];
var flag = 0;
foreach package_array ( pkgs ) {
var release = NULL;
var prefix = NULL;
var reference = NULL;
if (!empty_or_null(package_array['release'])) release = package_array['release'];
if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
if (release && prefix && reference) {
if (deb_check(release:release, prefix:prefix, reference:reference)) flag++;
}
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : deb_report_get()
);
exit(0);
}
else
{
var tested = deb_pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'caja-nextcloud / dolphin-nextcloud / libnextcloudsync-dev / etc');
}
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22895
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-32728
www.nessus.org/u?1c0ae60e
bugs.debian.org/cgi-bin/bugreport.cgi?bug=989846
packages.debian.org/source/bullseye/nextcloud-desktop
packages.debian.org/source/buster/nextcloud-desktop
security-tracker.debian.org/tracker/CVE-2021-22895
security-tracker.debian.org/tracker/CVE-2021-32728
www.debian.org/security/2021/dsa-4974
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
82.6%