Division by zero in libvncserver (Alpine package)

1) Division by zero

EUVDB-ID: #VU48699

Risk: Medium

CVSSv4.0: 6.6 [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/E:U/U:Green]

CVE-ID: CVE-2020-25708

CWE-ID: CWE-369 - Divide By Zero

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to divide by zero error when processed by the VNC server, would lead to a floating point exception, resulting in a denial of service. A remote attacker can pass specially crafted file to the application and crash it.

Mitigation

Install update from vendor's website.

Vulnerable software versions

libvncserver (Alpine package): 0.9.12-r2 - 0.9.13-r1

CPE2.3

• cpe:2.3:a:alpine:libvncserver_alpine_package:0.9.12-r2:*:*:*:*:alpine_linux:*:3.12
• cpe:2.3:a:alpine:libvncserver_alpine_package:0.9.13-r0:*:*:*:*:alpine_linux:*:3.12
• cpe:2.3:a:alpine:libvncserver_alpine_package:0.9.13-r1:*:*:*:*:alpine_linux:*:3.12

External links

https://git.alpinelinux.org/aports/commit/?id=e990657d3b8482a483f6dbd94eca267b4134e2a4

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.