SB2020093045 - Red Hat Enterprise Linux 7 update for tigervnc
Published: September 30, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Use-after-return (CVE-ID: CVE-2019-15691)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. A remote attacker can execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
2) Out-of-bounds write (CVE-ID: CVE-2019-15692)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to incorrect value checks. A remote attacker can trigger out-of-bounds write from "CopyRectDecoder" and execute arbitrary code on the target system.
3) Heap-based buffer overflow (CVE-ID: CVE-2019-15693)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error in "TightDecoder::FilterGradient". A remote attacker can trigger heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
4) Heap-based buffer overflow (CVE-ID: CVE-2019-15694)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to the signedness error in processing MemOutStream. A remote attacker can trigger heap-based buffer overflow from DecodeManager::decodeRect and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
5) Out-of-bounds write (CVE-ID: CVE-2019-15695)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to insufficient sanitization of PixelFormat. A remote attacker can trigger out-of-bounds write from "CMsgReader::readSetCursor" and execute arbitrary code on the target system.
Remediation
Install update from vendor's website.