SB2019020408 - Debian update for libvncserver
Published: February 4, 2019 Updated: February 11, 2019
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 9 vulnerabilities.
1) Heap use-after-free (CVE-ID: CVE-2018-6307)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to heap use-after-free error in server code of file transfer extension. A remote attacker can trigger memory corruption and execute arbitrary code with elevated privileges.
Successful exploitation of the vulnerability may result in system compromise.
2) Use-after-free (CVE-ID: CVE-2018-15126)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a heap use-after-free error in server code of file transfer extension. A remote attacker can trigger memory corruption and execute arbitrary code with elevated privileges.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
3) Heap out-of-bounds write (CVE-ID: CVE-2018-15127)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to heap out-of-bounds write in server code of file transfer extension. A remote attacker can trigger memory corruption and execute arbitrary code with elevated privileges.
Successful exploitation of the vulnerability may result in system compromise.
4) Heap out-of-bounds write (CVE-ID: CVE-2018-20019)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to heap out-of-bounds write in VNC client code. A remote attacker can trigger memory corruption and execute arbitrary code with elevated privileges.
Successful exploitation of the vulnerability may result in system compromise.
5) Heap out-of-bounds write (CVE-ID: CVE-2018-20020)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to heap out-of-bounds write in inside structure in VNC client code. A remote attacker can trigger memory corruption and execute arbitrary code with elevated privileges.
Successful exploitation of the vulnerability may result in system compromise.
6) Infinite loop (CVE-ID: CVE-2018-20021)
CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to infinite loop in VNC client code. A remote attacker can consume excessive amount of resources like CPU and RAM and perform a denial of service (DoS) attack.
7) Memory leak (CVE-ID: CVE-2018-20022)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to obtain potentially sensitive information.
The vulnerability exists due memory leak in VNC Repeater client code. A remote attacker can read stack memory and bypass ASLR.
8) Memory leak (CVE-ID: CVE-2018-20023)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to obtain potentially sensitive information.
The vulnerability exists due memory leak in VNC Repeater client code. A remote attacker can read stack memory and bypass ASLR.
9) NULL pointer dereference (CVE-ID: CVE-2018-20024)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in VNC client code. A remote attacker can perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.