SB2018032705 - SUSE Linux update for LibVNCServer
Published: March 27, 2018
Security Bulletin ID
SB2018032705
Severity
Medium
Patch available
YES
Number of vulnerabilities
3
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Heap-based buffer overflow (CVE-ID: CVE-2016-9941)
The vulnerability allows a remote attacker to execute arbitrary code on vulnerable client system.A heap-based buffer overflow vulnerability exists due to boundary error in rfbproto.c in LibVNCClient software, which is bundled with LibVNCServer. A remote attacker can trick the victim to connect to malicious VNC server, send a specially crafted FramebufferUpdate message containing a subrectangle outside of the client drawing area and trigger buffer overflow.
Successful exploitation of the vulnerability may allow an attacker to execute arbitrary code on vulnerable VNC client.
2) Heap-based buffer overflow (CVE-ID: CVE-2016-9942)
The vulnerability allows a remote attacker to execute arbitrary code on vulnerable client system.A heap-based buffer overflow vulnerability exists due to boundary error in ultra.c in LibVNCClient software, which is bundled with LibVNCServer. A remote attacker can trick the victim to connect to malicious VNC server, send a specially crafted FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed length exceeds what is specified by the tile dimensions, and trigger buffer overflow.
Successful exploitation of the vulnerability may allow an attacker to execute arbitrary code on vulnerable VNC client.
3) Integer overflow (CVE-ID: CVE-2018-7225)
The vulnerability allows a remote attacker to obtain potentially sensitive information.
The weakness exists in the rfbProcessClientNormalMessage() function due to integer overflow. A remote attacker can trigger memory corruption and gain access to potentially sensitive information.
Remediation
Install update from vendor's website.