#VU29378 Integer overflow in LibVNCServer - CVE-2020-14401

Vulnerability identifier: #VU29378

Vulnerability 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-2020-14401

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
LibVNCServer
Server applications / Remote management servers, RDP, SSH

Vendor: LibVNC

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to integer overflow in libvncserver/scale.c when processing data passed via pixel_value. A remote attacker can pass specially crafted data to the application, trigger integer 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

LibVNCServer: 0.9.0 - 0.9.12

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External links
https://github.com/LibVNC/libvncserver/commit/a6788d1da719ae006605b78d22f5a9f170b423af
https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13

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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.