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
AI Score
Confidence
High
EPSS
Percentile
96.1%
The version of tigervnc installed on the remote host is prior to 1.12.0 / 1.13.1. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2024-021-01 advisory.
A flaw was found in xorg-server. Querying or changing XKB button actions such as moving from a touchpad to a mouse can result in out-of-bounds memory reads and writes. This may allow local privilege escalation or possible remote code execution in cases where X11 forwarding is involved. (CVE-2023-6377)
A flaw was found in xorg-server. A specially crafted request to RRChangeProviderProperty or RRChangeOutputProperty can trigger an integer overflow which may lead to a disclosure of sensitive information. (CVE-2023-6478)
A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255, but the X.Org Server was only allocating space for the device’s particular number of buttons, leading to a heap overflow if a bigger value was used. (CVE-2023-6816)
A flaw was found in the X.Org server. The GLX PBuffer code does not call the XACE hook when creating the buffer, leaving it unlabeled. When the client issues another request to access that resource (as with a GetGeometry) or when it creates another resource that needs to access that buffer, such as a GC, the XSELINUX code will try to use an object that was never labeled and crash because the SID is NULL.
(CVE-2024-0408)
A flaw was found in the X.Org server. The cursor code in both Xephyr and Xwayland uses the wrong type of private at creation. It uses the cursor bits type with the cursor as private, and when initiating the cursor, that overwrites the XSELINUX context. (CVE-2024-0409)
The X.Org project reports: Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255 but the X.Org Server was only allocating space for the device’s number of buttons, leading to a heap overflow if a bigger value was used. If a device has both a button class and a key class and numButtons is zero, we can get an out-of-bounds write due to event under- allocation in the DeliverStateNotifyEvent function. The XISendDeviceHierarchyEvent() function allocates space to store up to MAXDEVICES (256) xXIHierarchyInfo structures in info.
If a device with a given ID was removed and a new device with the same ID added both in the same operation, the single device ID will lead to two info structures being written to info. Since this case can occur for every device ID at once, a total of two times MAXDEVICES info structures might be written to the allocation, leading to a heap buffer overflow. The DisableDevice() function is called whenever an enabled device is disabled and it moves the device from the inputInfo.devices linked list to the inputInfo.off_devices linked list. However, its link/unlink operation has an issue during the recursive call to DisableDevice() due to the prev pointer pointing to a removed device. This issue leads to a length mismatch between the total number of devices and the number of device in the list, leading to a heap overflow and, possibly, to local privilege escalation.
(CVE-2024-0229, CVE-2024-21885, CVE-2024-21886)
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
#
# The descriptive text and package checks in this plugin were
# extracted from Slackware Security Advisory SSA:2024-021-01. The text
# itself is copyright (C) Slackware Linux, Inc.
##
include('compat.inc');
if (description)
{
script_id(189266);
script_version("1.1");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/29");
script_cve_id(
"CVE-2023-6377",
"CVE-2023-6478",
"CVE-2023-6816",
"CVE-2024-0229",
"CVE-2024-0408",
"CVE-2024-0409",
"CVE-2024-21885",
"CVE-2024-21886"
);
script_name(english:"Slackware Linux 15.0 / current tigervnc Multiple Vulnerabilities (SSA:2024-021-01)");
script_set_attribute(attribute:"synopsis", value:
"The remote Slackware Linux host is missing a security update to tigervnc.");
script_set_attribute(attribute:"description", value:
"The version of tigervnc installed on the remote host is prior to 1.12.0 / 1.13.1. It is, therefore, affected by multiple
vulnerabilities as referenced in the SSA:2024-021-01 advisory.
- A flaw was found in xorg-server. Querying or changing XKB button actions such as moving from a touchpad to
a mouse can result in out-of-bounds memory reads and writes. This may allow local privilege escalation or
possible remote code execution in cases where X11 forwarding is involved. (CVE-2023-6377)
- A flaw was found in xorg-server. A specially crafted request to RRChangeProviderProperty or
RRChangeOutputProperty can trigger an integer overflow which may lead to a disclosure of sensitive
information. (CVE-2023-6478)
- A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for
each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255, but the
X.Org Server was only allocating space for the device's particular number of buttons, leading to a heap
overflow if a bigger value was used. (CVE-2023-6816)
- A flaw was found in the X.Org server. The GLX PBuffer code does not call the XACE hook when creating the
buffer, leaving it unlabeled. When the client issues another request to access that resource (as with a
GetGeometry) or when it creates another resource that needs to access that buffer, such as a GC, the
XSELINUX code will try to use an object that was never labeled and crash because the SID is NULL.
(CVE-2024-0408)
- A flaw was found in the X.Org server. The cursor code in both Xephyr and Xwayland uses the wrong type of
private at creation. It uses the cursor bits type with the cursor as private, and when initiating the
cursor, that overwrites the XSELINUX context. (CVE-2024-0409)
- The X.Org project reports: Both DeviceFocusEvent and the XIQueryPointer reply contain a bit
for each logical button currently down. Buttons can be arbitrarily mapped to any value up to
255 but the X.Org Server was only allocating space for the device's number of buttons,
leading to a heap overflow if a bigger value was used. If a device has both a button class and a key class
and numButtons is zero, we can get an out-of-bounds write due to event under-
allocation in the DeliverStateNotifyEvent function. The XISendDeviceHierarchyEvent() function
allocates space to store up to MAXDEVICES (256) xXIHierarchyInfo structures in info.
If a device with a given ID was removed and a new device with the same ID added both in the
same operation, the single device ID will lead to two info structures being
written to info. Since this case can occur for every device ID at once, a total of
two times MAXDEVICES info structures might be written to the allocation, leading to a heap
buffer overflow. The DisableDevice() function is called whenever an enabled device is disabled
and it moves the device from the inputInfo.devices linked list to the inputInfo.off_devices
linked list. However, its link/unlink operation has an issue during the recursive
call to DisableDevice() due to the prev pointer pointing to a removed device. This
issue leads to a length mismatch between the total number of devices and the number of device
in the list, leading to a heap overflow and, possibly, to local privilege escalation.
(CVE-2024-0229, CVE-2024-21885, CVE-2024-21886)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
# http://www.slackware.com/security/viewer.php?l=slackware-security&y=2024&m=slackware-security.374309
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c3795412");
script_set_attribute(attribute:"solution", value:
"Upgrade the affected tigervnc package.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
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-2023-6816");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_set_attribute(attribute:"vuln_publication_date", value:"2023/12/13");
script_set_attribute(attribute:"patch_publication_date", value:"2024/01/21");
script_set_attribute(attribute:"plugin_publication_date", value:"2024/01/21");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:slackware:slackware_linux:tigervnc");
script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux");
script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:15.0");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Slackware Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/Slackware/release", "Host/Slackware/packages");
exit(0);
}
include("slackware.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Slackware/release")) audit(AUDIT_OS_NOT, "Slackware");
if (!get_kb_item("Host/Slackware/packages")) audit(AUDIT_PACKAGE_LIST_MISSING);
var cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Slackware", cpu);
var flag = 0;
var constraints = [
{ 'fixed_version' : '1.12.0', 'product' : 'tigervnc', 'os_name' : 'Slackware Linux', 'os_version' : '15.0', 'service_pack' : '5_slack15.0', 'arch' : 'i586' },
{ 'fixed_version' : '1.12.0', 'product' : 'tigervnc', 'os_name' : 'Slackware Linux', 'os_version' : '15.0', 'service_pack' : '5_slack15.0', 'arch' : 'x86_64' },
{ 'fixed_version' : '1.13.1', 'product' : 'tigervnc', 'os_name' : 'Slackware Linux', 'os_version' : 'current', 'service_pack' : '3', 'arch' : 'i586' },
{ 'fixed_version' : '1.13.1', 'product' : 'tigervnc', 'os_name' : 'Slackware Linux', 'os_version' : 'current', 'service_pack' : '3', 'arch' : 'x86_64' }
];
foreach var constraint (constraints) {
var pkg_arch = constraint['arch'];
var arch = NULL;
if (pkg_arch == "x86_64") {
arch = pkg_arch;
}
if (slackware_check(osver:constraint['os_version'],
arch:arch,
pkgname:constraint['product'],
pkgver:constraint['fixed_version'],
pkgarch:pkg_arch,
pkgnum:constraint['service_pack'])) flag++;
}
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_HOLE,
extra : slackware_report_get()
);
exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6377
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6478
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-6816
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-0229
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-0408
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-0409
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-21885
cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-21886
www.nessus.org/u?c3795412
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
AI Score
Confidence
High
EPSS
Percentile
96.1%