Multiple vulnerabilities in TigerVNC



| Updated: 2020-01-03
Risk High
Patch available YES
Number of vulnerabilities 5
CVE-ID CVE-2019-15695
CVE-2019-15693
CVE-2019-15692
CVE-2019-15691
CVE-2019-15694
CWE-ID CWE-787
CWE-122
CWE-672
Exploitation vector Network
Public exploit N/A
Vulnerable software
 TigerVNC
Web applications / Modules and components for CMS

Vendor tigervnc.org

Security Bulletin

This security bulletin contains information about 5 vulnerabilities.

1) Out-of-bounds write

EUVDB-ID: #VU23908

Risk: High

CVSSv4.0: 8.1 [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/E:U/U:Amber]

CVE-ID: CVE-2019-15695

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

TigerVNC: 0.0.90 - 1.10.0

CPE2.3 External links

https://github.com/CendioOssman/tigervnc/commit/05e28490873a861379c943bf616614b78b558b89
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
https://www.openwall.com/lists/oss-security/2019/12/20/2
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2020/03/23/klcert-20-008-remote-code-execution-on-tigervnc-version-prior-to-1-10-1-2/


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Heap-based buffer overflow

EUVDB-ID: #VU23907

Risk: High

CVSSv4.0: 8.1 [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/E:U/U:Amber]

CVE-ID: CVE-2019-15693

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

TigerVNC: 0.0.90 - 1.10.0

CPE2.3 External links

https://github.com/CendioOssman/tigervnc/commit/b4ada8d0c6dac98c8b91fc64d112569a8ae5fb95
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
https://www.openwall.com/lists/oss-security/2019/12/20/2
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2020/03/23/klcert-20-007-remote-code-execution-on-tigervnc-version-prior-to-1-10-1/


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Out-of-bounds write

EUVDB-ID: #VU23906

Risk: High

CVSSv4.0: 8.1 [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/E:U/U:Amber]

CVE-ID: CVE-2019-15692

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

TigerVNC: 0.0.90 - 1.10.0

CPE2.3 External links

https://github.com/CendioOssman/tigervnc/commit/996356b6c65ca165ee1ea46a571c32a1dc3c3821
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
https://www.openwall.com/lists/oss-security/2019/12/20/2
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2020/03/23/klcert-20-006-remote-code-execution-on-tigervnc-version-prior-to-1-10-1/


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Use-after-return

EUVDB-ID: #VU23905

Risk: High

CVSSv4.0: 8.1 [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/E:U/U:Amber]

CVE-ID: CVE-2019-15691

CWE-ID: CWE-672 - Operation on a Resource after Expiration or Release

Exploit availability: No

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

TigerVNC: 0.0.90 - 1.10.0

CPE2.3 External links

https://github.com/CendioOssman/tigervnc/commit/d61a767d6842b530ffb532ddd5a3d233119aad40
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
https://www.openwall.com/lists/oss-security/2019/12/20/2
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2020/03/23/klcert-20-005-remote-code-execution-on-tigervnc-version-prior-to-1-10-1/


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Heap-based buffer overflow

EUVDB-ID: #VU23903

Risk: High

CVSSv4.0: 8.1 [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/E:U/U:Amber]

CVE-ID: CVE-2019-15694

CWE-ID: CWE-122 - Heap-based Buffer Overflow

Exploit availability: No

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

TigerVNC: 0.0.90 - 1.10.0

CPE2.3 External links

https://github.com/CendioOssman/tigervnc/commit/0943c006c7d900dfc0281639e992791d6c567438
https://github.com/TigerVNC/tigervnc/releases/tag/v1.10.1
https://www.openwall.com/lists/oss-security/2019/12/20/2
https://ics-cert.kaspersky.com/advisories/klcert-advisories/2020/03/23/klcert-20-008-remote-code-execution-on-tigervnc-version-prior-to-1-10-1/


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



###SIDEBAR###