Synopsis
The remote Debian host is missing a security update.
Description
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.
Solution
Upgrade the affected packages.