CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
98.1%
Kaspersky Lab discovered several vulnerabilities in libvncserver, a C library to implement VNC server/client functionalities.
CVE-2018-6307
a heap use-after-free vulnerability in the server code of the file transfer extension, which can result in remote code execution. This attack appears to be exploitable via network connectivity.
CVE-2018-15127
contains a heap out-of-bound write vulnerability in the server code of the file transfer extension, which can result in remote code execution. This attack appears to be exploitable via network connectivity.
CVE-2018-20019
multiple heap out-of-bound write vulnerabilities in VNC client code, which can result in remote code execution.
CVE-2018-20020
heap out-of-bound write vulnerability in a structure in VNC client code, which can result in remote code execution.
CVE-2018-20021
CWE-835: Infinite Loop vulnerability in VNC client code. The vulnerability could allow an attacker to consume an excessive amount of resources, such as CPU and RAM.
CVE-2018-20022
CWE-665: Improper Initialization weaknesses in VNC client code, which could allow an attacker to read stack memory and can be abused for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and bypass ASLR.
CVE-2018-20023
Improper Initialization vulnerability in VNC Repeater client code, which could allow an attacker to read stack memory and can be abused for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and bypass ASLR.
CVE-2018-20024
a NULL pointer dereference in VNC client code, which can result in DoS.
For Debian 8 ‘Jessie’, these problems have been fixed in version 0.9.9+dfsg2-6.1+deb8u4.
We recommend that you upgrade your libvncserver packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1617-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(119877);
script_version("1.7");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/11");
script_cve_id("CVE-2018-15127", "CVE-2018-20019", "CVE-2018-20020", "CVE-2018-20021", "CVE-2018-20022", "CVE-2018-20023", "CVE-2018-20024", "CVE-2018-6307");
script_name(english:"Debian DLA-1617-1 : libvncserver security update");
script_summary(english:"Checks dpkg output for the updated packages.");
script_set_attribute(
attribute:"synopsis",
value:"The remote Debian host is missing a security update."
);
script_set_attribute(
attribute:"description",
value:
"Kaspersky Lab discovered several vulnerabilities in libvncserver, a C
library to implement VNC server/client functionalities.
CVE-2018-6307
a heap use-after-free vulnerability in the server code of the file
transfer extension, which can result in remote code execution. This
attack appears to be exploitable via network connectivity.
CVE-2018-15127
contains a heap out-of-bound write vulnerability in the server code of
the file transfer extension, which can result in remote code
execution. This attack appears to be exploitable via network
connectivity.
CVE-2018-20019
multiple heap out-of-bound write vulnerabilities in VNC client code,
which can result in remote code execution.
CVE-2018-20020
heap out-of-bound write vulnerability in a structure in VNC client
code, which can result in remote code execution.
CVE-2018-20021
CWE-835: Infinite Loop vulnerability in VNC client code. The
vulnerability could allow an attacker to consume an excessive amount
of resources, such as CPU and RAM.
CVE-2018-20022
CWE-665: Improper Initialization weaknesses in VNC client code, which
could allow an attacker to read stack memory and can be abused for
information disclosure. Combined with another vulnerability, it can be
used to leak stack memory layout and bypass ASLR.
CVE-2018-20023
Improper Initialization vulnerability in VNC Repeater client code,
which could allow an attacker to read stack memory and can be abused
for information disclosure. Combined with another vulnerability, it
can be used to leak stack memory layout and bypass ASLR.
CVE-2018-20024
a NULL pointer dereference in VNC client code, which can result in
DoS.
For Debian 8 'Jessie', these problems have been fixed in version
0.9.9+dfsg2-6.1+deb8u4.
We recommend that you upgrade your libvncserver packages.
NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA security advisory. Tenable has attempted
to automatically clean and format it as much as possible without
introducing additional issues."
);
script_set_attribute(
attribute:"see_also",
value:"https://lists.debian.org/debian-lts-announce/2018/12/msg00017.html"
);
script_set_attribute(
attribute:"see_also",
value:"https://packages.debian.org/source/jessie/libvncserver"
);
script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-20020");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncclient0");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncclient0-dbg");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncserver-config");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncserver-dev");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncserver0");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncserver0-dbg");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:linuxvnc");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/19");
script_set_attribute(attribute:"patch_publication_date", value:"2018/12/26");
script_set_attribute(attribute:"plugin_publication_date", value:"2018/12/27");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2018-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_family(english:"Debian Local Security Checks");
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/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (deb_check(release:"8.0", prefix:"libvncclient0", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (deb_check(release:"8.0", prefix:"libvncclient0-dbg", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (deb_check(release:"8.0", prefix:"libvncserver-config", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (deb_check(release:"8.0", prefix:"libvncserver-dev", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (deb_check(release:"8.0", prefix:"libvncserver0", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (deb_check(release:"8.0", prefix:"libvncserver0-dbg", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (deb_check(release:"8.0", prefix:"linuxvnc", reference:"0.9.9+dfsg2-6.1+deb8u4")) flag++;
if (flag)
{
if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
else security_hole(0);
exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
Vendor | Product | Version | CPE |
---|---|---|---|
debian | debian_linux | libvncclient0 | p-cpe:/a:debian:debian_linux:libvncclient0 |
debian | debian_linux | libvncclient0-dbg | p-cpe:/a:debian:debian_linux:libvncclient0-dbg |
debian | debian_linux | libvncserver-config | p-cpe:/a:debian:debian_linux:libvncserver-config |
debian | debian_linux | libvncserver-dev | p-cpe:/a:debian:debian_linux:libvncserver-dev |
debian | debian_linux | libvncserver0 | p-cpe:/a:debian:debian_linux:libvncserver0 |
debian | debian_linux | libvncserver0-dbg | p-cpe:/a:debian:debian_linux:libvncserver0-dbg |
debian | debian_linux | linuxvnc | p-cpe:/a:debian:debian_linux:linuxvnc |
debian | debian_linux | 8.0 | cpe:/o:debian:debian_linux:8.0 |
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-15127
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20019
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20020
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20021
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20022
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20023
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20024
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6307
lists.debian.org/debian-lts-announce/2018/12/msg00017.html
packages.debian.org/source/jessie/libvncserver
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
98.1%