Multiple vulnerabilities in Rockwell Automation FactoryTalk Linx

Published: 2020-12-28 | Updated: 2021-01-29

Risk	Medium
Patch available	NO
Number of vulnerabilities	4
CVE-ID	CVE-2020-5801 CVE-2020-5802 CVE-2020-5806 CVE-2020-5807
CWE-ID	CWE-248 CWE-789 CWE-20
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available. Public exploit code for vulnerability #3 is available. Public exploit code for vulnerability #4 is available.
Vulnerable software	FactoryTalk Linx Server applications / SCADA systems
Vendor	Rockwell Automation

Security Bulletin

This security bulletin contains information about 4 vulnerabilities.

Updated: 29.01.2021

Added vulnerability #VU49159, added links to ISC-CERT.

1) Uncaught Exception

EUVDB-ID: #VU49156

Risk: Medium

CVSSv4.0: 7.7 [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:P/U:Green]

CVE-ID: CVE-2020-5801

CWE-ID: CWE-248 - Uncaught Exception

Exploit availability: Yes

Description

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

The vulnerability exists due to an uncaught exception when processing OpenNamespace messages. The OpenNamespace message is sent to TCP port 4241 to obtain a session identifier. Subsequent requests require a valid session-id to interact with the service listening on that port. In the OpenNamespace message, the session-id field in the message header should be absent or empty. If a second OpenNamespace request is sent with a valid session-id in it, the CFTLDManager::HandleRequest function in RnaDaSvr.dll loaded in RSLinxNG.exe leads to unhandled exception, resulting in termination of RSLinxNG.exe.

A remote non-authenticated attacker can send a malformed request and crash the RSLinxNG.exe service.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

FactoryTalk Linx: 6.00 - 6.20

CPE2.3

External links

https://www.tenable.com/security/research/tra-2020-71
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129496/redirect
https://ics-cert.us-cert.gov/advisories/icsa-21-028-01

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Uncontrolled memory allocation

EUVDB-ID: #VU49157

Risk: Medium

CVSSv4.0: 7.7 [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:P/U:Green]

CVE-ID: CVE-2020-5802

CWE-ID: CWE-789 - Uncontrolled Memory Allocation

Exploit availability: Yes

Description

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

The vulnerability exists due to an uncontrolled memory allocation in RSLinxNG.exe. An attacker-controlled memory allocation size can be passed to the C++ new operator in RnaDaSvr.dll by sending a specially crafted ConfigureItems message to TCP prot 4241. This will cause the new operator to allocate a large amount of memory. It's been observed that a large allocation size (i.e., 0xfffffff3) can cause an unhandled exception in RSLinxNG.exe, which results in process termination of RSLinxNG.exe.

A remote non-authenticated attacker can send a malformed request and crash the RSLinxNG.exe service.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

FactoryTalk Linx: 6.00 - 6.20

CPE2.3

External links

https://www.tenable.com/security/research/tra-2020-71
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129496/redirect
https://ics-cert.us-cert.gov/advisories/icsa-21-028-01

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Uncontrolled memory allocation

EUVDB-ID: #VU49158

Risk: Low

CVSSv4.0: 5.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2020-5806

CWE-ID: CWE-789 - Uncontrolled Memory Allocation

Exploit availability: Yes

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to uncontrolled memory allocation in RSLinxNG.exe. An attacker-controlled memory allocation size can be passed to the C++ new operator in the CServerManager::HandleBrowseLoadIconStreamRequest function in messaging.dll. A local attacker can send a specially crafted LoadIconStream message to 127.0.0.1:7153 to cause the new operator to allocate a large amount of memory. It's been observed that a large allocation size (i.e., 0xffffffff) can cause an unhandled exception in RSLinxNG.exe, which results in process termination of RSLinxNG.exe.

A local user can perform a denial of service attack.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

FactoryTalk Linx: 6.10 - 6.20

CPE2.3

External links

https://www.tenable.com/security/research/tra-2020-71
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129496/redirect
https://ics-cert.us-cert.gov/advisories/icsa-21-028-01

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Input validation error

EUVDB-ID: #VU49159

Risk: Medium

CVSSv4.0: 5.2 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2020-5807

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

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

The vulnerability exists due to insufficient validation of user-supplied input. An unauthenticated remote attacker can send data to RsvcHost.exe listening on TCP port 5241 to add entries in the FactoryTalk Diagnostics event log. A local user can use the FactoryTalk Diagnostics Viewer (FTDiagViewer.exe) to view the log. The attacker can specify long fields in the log entry, which can cause an unhandled exception by wcscpy_s() in FTDiagnosticsViewer.dll loaded in FTDiagViewer.exe, resulting in process termination.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

FactoryTalk Linx: 6.00 - 6.20

CPE2.3

External links

https://ics-cert.us-cert.gov/advisories/icsa-21-028-01

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.