openEuler 20.03 LTS update for tigervnc

1) Improper Certificate Validation

EUVDB-ID: #VU47533

Risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26117

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a MitM attack.

The vulnerability exists due to improper TLS certificate validation in rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC. Any previously accepted certificate will be considered trusted, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

openEuler: 20.03 LTS

tigervnc-server-module: before 1.10.1-6

tigervnc-debugsource: before 1.10.1-6

tigervnc-debuginfo: before 1.10.1-6

tigervnc-server: before 1.10.1-6

tigervnc-server-applet: before 1.10.1-6

tigervnc-help: before 1.10.1-6

tigervnc-server-minimal: before 1.10.1-6

tigervnc: before 1.10.1-6

External links

http://www.openeuler.org/en/security/security-bulletins/detail/?id=openEuler-SA-2020-1105

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.