CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
85.5%
It was discovered that there were two vulnerabilities in libvncserver, a library to create/embed a VNC server :
CVE-2016-9941: Fix a heap-based buffer overflow that allows remote servers to cause a denial of service via a crafted FramebufferUpdate message containing a subrectangle outside of the drawing area.
CVE-2016-9942: Fix a heap-based buffer overflow that allow remote servers to cause a denial of service via a crafted FramebufferUpdate message with the ‘Ultra’ type tile such that the LZO decompressed payload exceeds the size of the tile dimensions.
For Debian 7 ‘Wheezy’, these issues have been fixed in libvncserver version 0.9.9+dfsg-1+deb7u2.
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-777-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(96272);
script_version("3.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/11");
script_name(english:"Debian DLA-777-1 : 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:
"It was discovered that there were two vulnerabilities in libvncserver,
a library to create/embed a VNC server :
- CVE-2016-9941: Fix a heap-based buffer overflow that
allows remote servers to cause a denial of service via a
crafted FramebufferUpdate message containing a
subrectangle outside of the drawing area.
- CVE-2016-9942: Fix a heap-based buffer overflow that
allow remote servers to cause a denial of service via a
crafted FramebufferUpdate message with the 'Ultra' type
tile such that the LZO decompressed payload exceeds the
size of the tile dimensions.
For Debian 7 'Wheezy', these issues have been fixed in libvncserver
version 0.9.9+dfsg-1+deb7u2.
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/2017/01/msg00005.html"
);
script_set_attribute(
attribute:"see_also",
value:"https://packages.debian.org/source/wheezy/libvncserver"
);
script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
script_set_attribute(attribute:"risk_factor", value:"High");
script_set_attribute(attribute:"plugin_type", value:"local");
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:7.0");
script_set_attribute(attribute:"patch_publication_date", value:"2017/01/03");
script_set_attribute(attribute:"plugin_publication_date", value:"2017/01/04");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2017-2021 Tenable Network Security, Inc.");
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:"7.0", prefix:"libvncserver-config", reference:"0.9.9+dfsg-1+deb7u2")) flag++;
if (deb_check(release:"7.0", prefix:"libvncserver-dev", reference:"0.9.9+dfsg-1+deb7u2")) flag++;
if (deb_check(release:"7.0", prefix:"libvncserver0", reference:"0.9.9+dfsg-1+deb7u2")) flag++;
if (deb_check(release:"7.0", prefix:"libvncserver0-dbg", reference:"0.9.9+dfsg-1+deb7u2")) flag++;
if (deb_check(release:"7.0", prefix:"linuxvnc", reference:"0.9.9+dfsg-1+deb7u2")) 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");
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:P/I:P/A:P
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
85.5%