Detections
Analytics
Amazon Linux AMI : tigervnc (ALAS-2017-879)
critical Nessus Plugin ID 102867
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Synopsis
The remote Amazon Linux AMI host is missing a security update.Description
Buffer overflow in ModifiablePixelBuffer::fillRectA buffer overflow flaw, leading to memory corruption, was found in TigerVNC viewer. A remote malicious VNC server could use this flaw to crash the client vncviewer process resulting in denial of service.
(CVE-2017-5581)
VNC server can crash when TLS handshake terminates early :
A denial of service flaw was found in the TigerVNC's Xvnc server. A remote unauthenticated attacker could use this flaw to make Xvnc crash by terminating the TLS handshake process early. (CVE-2016-10207)
SSecurityVeNCrypt memory leak :
A memory leak flaw was found in the way TigerVNC handled termination of VeNCrypt connections. A remote unauthenticated attacker could repeatedly send connection requests to the Xvnc server, causing it to consume large amounts of memory resources over time, and ultimately leading to a denial of service due to memory exhaustion.
(CVE-2017-7392)
Double free via crafted fences :
A double free flaw was found in the way TigerVNC handled ClientFence messages. A remote, authenticated attacker could use this flaw to make Xvnc crash by sending specially crafted ClientFence messages, resulting in denial of service. (CVE-2017-7393)
Server crash via long usernames :
A missing input sanitization flaw was found in the way TigerVNC handled credentials. A remote unauthenticated attacker could use this flaw to make Xvnc crash by sending specially crafted usernames, resulting in denial of service. (CVE-2017-7394)
Integer overflow in SMsgReader::readClientCutText :
An integer overflow flaw was found in the way TigerVNC handled ClientCutText messages. A remote, authenticated attacker could use this flaw to make Xvnc crash by sending specially crafted ClientCutText messages, resulting in denial of service.
(CVE-2017-7395)
SecurityServer and ClientServer memory leaks :
A memory leak flaw was found in the way TigerVNC handled client connections. A remote unauthenticated attacker could repeatedly send connection requests to the Xvnc server, causing it to consume large amounts of memory resources over time, and ultimately leading to a denial of service due to memory exhaustion. (CVE-2017-7396)
Solution
Run 'yum update tigervnc' to update your system.See Also
Plugin Details
Severity: Critical
ID: 102867
File Name: ala_ALAS-2017-879.nasl
Version: 3.2
Type: local
Agent: unix
Published: 9/1/2017
Updated: 4/18/2018
Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 5.9
CVSS v2
Risk Factor: Medium
Base Score: 6.8
Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P
CVSS v3
Risk Factor: Critical
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability Information
CPE: p-cpe:/a:amazon:linux:tigervnc-server-module, p-cpe:/a:amazon:linux:tigervnc-debuginfo, p-cpe:/a:amazon:linux:tigervnc, p-cpe:/a:amazon:linux:tigervnc-server, cpe:/o:amazon:linux
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Patch Publication Date: 8/31/2017
Reference Information
CVE: CVE-2016-10207, CVE-2017-5581, CVE-2017-7392, CVE-2017-7393, CVE-2017-7394, CVE-2017-7395, CVE-2017-7396
ALAS: 2017-879