Package        : libvncserver
Version        : 0.9.9+dfsg2-6.1+deb8u4
CVE ID         : CVE-2018-6307 CVE-2018-15127 CVE-2018-20019
                 CVE-2018-20020 CVE-2018-20021 CVE-2018-20022
                 CVE-2018-20023 CVE-2018-20024
Debian Bug     : 916941


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.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS