#VU21207 Improper access control in WebAccess/SCADA - CVE-2019-3941

Vulnerability identifier: #VU21207

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-3941

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
WebAccess/SCADA
Server applications / SCADA systems

Vendor: Advantech Co., Ltd

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to the "webvrpcs.exe" accepts unauthenticated RPC calls to perform remote file operations including fopen, fseek, ftell, fread, fwrite, and fclose. A remote attacker can send a specially crafted IOCTL 10005 RPC call to the application, bypass implemented security restrictions and download arbitrary files from the remote host.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

WebAccess/SCADA: 8.3.4

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External links
https://www.tenable.com/security/research/tra-2019-15

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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.