Zero-day vulnerability in SIMATIC STEP 7

DDL hijacking
CVE-2012-3015

The vulnerability was used by Stuxnet along with CVE-2010-2772.

Known malware:

Stuxnet

Vulnerability details

Advisory: SB2012072401 - Insecure DLL loading in SIMATIC STEP 7 and PCS 7

Vulnerable component: SIMATIC STEP 7

CVE-ID: CVE-2012-3015

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-426 - Untrusted Search Path

Description:

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to insecure DDL loading mechanism when processing STEP 7 files in SIMATIC STEP 7 and SIMATIC PCS 7 software. A remote attacker can trick the victim into opening a SETP 7 file from a remote SMB or WebDAV share, which hosts malicious .dll file, and execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Note: the vulnerability has been exploited in the wild by Stuxnet malware in 2010.

Known APT campaigns:

Iranian Nuclear Facilities breach

The breach was identified in summer 2010 by VirusBlokada antivirus company from Belarus, who was called to investigate computers in Iranian nuclear facilities.

External links:

http://www.siemens.com/cert/pool/cert/siemens_security_advisory_ssa-110665.pdf
https://ics-cert.us-cert.gov/advisories/ICSA-12-205-02

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.