CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
88.7%
The remote host is missing an update for the
# 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("1.3.6.1.4.1.25623.1.0.844508");
script_cve_id("CVE-2019-20839", "CVE-2019-20840", "CVE-2020-14396", "CVE-2020-14397", "CVE-2020-14398", "CVE-2020-14399", "CVE-2020-14400", "CVE-2020-14401", "CVE-2020-14402", "CVE-2020-14403", "CVE-2020-14404", "CVE-2020-14405");
script_tag(name:"creation_date", value:"2020-07-24 03:00:30 +0000 (Fri, 24 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:"6.4");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:P/A:P");
script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
script_tag(name:"severity_origin", value:"NVD");
script_tag(name:"severity_date", value:"2020-07-28 14:07:53 +0000 (Tue, 28 Jul 2020)");
script_name("Ubuntu: Security Advisory (USN-4434-1)");
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|20\.04\ LTS)");
script_xref(name:"Advisory-ID", value:"USN-4434-1");
script_xref(name:"URL", value:"https://ubuntu.com/security/notices/USN-4434-1");
script_tag(name:"summary", value:"The remote host is missing an update for the 'libvncserver' package(s) announced via the USN-4434-1 advisory.");
script_tag(name:"vuldetect", value:"Checks if a vulnerable package version is present on the target host.");
script_tag(name:"insight", value:"Ramin Farajpour Cami discovered that LibVNCServer incorrectly handled
certain malformed unix socket names. A remote attacker could exploit this
with a crafted socket name, leading to a denial of service, or possibly
execute arbitrary code. (CVE-2019-20839)
It was discovered that LibVNCServer did not properly access byte-aligned
data. A remote attacker could possibly use this issue to cause
LibVNCServer to crash, resulting in a denial of service. This issue only
affected Ubuntu 18.04 LTS and Ubuntu 16.04 LTS. (CVE-2019-20840)
Christian Beier discovered that LibVNCServer incorrectly handled anonymous
TLS connections. A remote attacker could possibly use this issue to cause
LibVNCServer to crash, resulting in a denial of service. This issue only
affected Ubuntu 20.04 LTS. (CVE-2020-14396)
It was discovered that LibVNCServer incorrectly handled region clipping. A
remote attacker could possibly use this issue to cause LibVNCServer to
crash, resulting in a denial of service. (CVE-2020-14397)
It was discovered that LibVNCServer did not properly reset incorrectly
terminated TCP connections. A remote attacker could possibly use this
issue to cause an infinite loop, resulting in a denial of service.
(CVE-2020-14398)
It was discovered that LibVNCServer did not properly access byte-aligned
data. A remote attacker could possibly use this issue to cause
LibVNCServer to crash, resulting in a denial of service. (CVE-2020-14399,
CVE-2020-14400)
It was discovered that LibVNCServer incorrectly handled screen scaling on
the server side. A remote attacker could use this issue to cause
LibVNCServer to crash, resulting in a denial of service, or possibly
execute arbitrary code. (CVE-2020-14401)
It was discovered that LibVNCServer incorrectly handled encodings. A
remote attacker could use this issue to cause LibVNCServer to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2020-14402, CVE-2020-14403, CVE-2020-14404)
It was discovered that LibVNCServer incorrectly handled TextChat messages.
A remote attacker could possibly use this issue to cause LibVNCServer to
crash, resulting in a denial of service. (CVE-2020-14405)");
script_tag(name:"affected", value:"'libvncserver' package(s) on Ubuntu 16.04, Ubuntu 18.04, 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:"libvncclient1", ver:"0.9.10+dfsg-3ubuntu0.16.04.5", rls:"UBUNTU16.04 LTS"))) {
report += res;
}
if(!isnull(res = isdpkgvuln(pkg:"libvncserver1", ver:"0.9.10+dfsg-3ubuntu0.16.04.5", 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:"libvncclient1", ver:"0.9.11+dfsg-1ubuntu1.3", rls:"UBUNTU18.04 LTS"))) {
report += res;
}
if(!isnull(res = isdpkgvuln(pkg:"libvncserver1", ver:"0.9.11+dfsg-1ubuntu1.3", rls:"UBUNTU18.04 LTS"))) {
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:"libvncclient1", ver:"0.9.12+dfsg-9ubuntu0.2", rls:"UBUNTU20.04 LTS"))) {
report += res;
}
if(!isnull(res = isdpkgvuln(pkg:"libvncserver1", ver:"0.9.12+dfsg-9ubuntu0.2", rls:"UBUNTU20.04 LTS"))) {
report += res;
}
if(report != "") {
security_message(data:report);
} else if(__pkg_match) {
exit(99);
}
exit(0);
}
exit(0);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
88.7%