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This alert update is a follow-up to the updated NCCIC/ICS-CERT Alert titled ICS-ALERT-14-099-01E Situational Awareness Alert for OpenSSL Vulnerability that was published April 29, 2014, on the ICS-CERT web site.
ICS-CERT is aware of a public report of a vulnerability with proof-of-concept (PoC) exploit code that could expose private secure sockets layer (SSL) keys used in the OpenSSL implementation of secure communication. According to this report, the vulnerability in OpenSSL Versions 1.0.1 through 1.0.1f contains a flaw in its implementation of the transport layer security/datagram transport layer security (TLS/DTLS) heartbeat functionality that could disclose private/encrypted information to an attacker. This vulnerability is commonly referred to as “heartbleed.” This vulnerability was discovered by a team of security engineers (Riku, Antti, and Matti) at Codenomicon and Neel Mehta of Google Security, who reported this vulnerability to the National Cyber Security Centre Finland (NCSC-FI) for vulnerability coordination and reporting to the OpenSSL team. This report was released without coordination with either the vendor or ICS-CERT. ICS-CERT is issuing this alert to provide early notice of the report and identify baseline mitigations for reducing risks to this and other cybersecurity attacks.
The report included vulnerability details and PoC exploit code for the following vulnerability:
|Vulnerability Type||Remotely Exploitable||Impact|
|Heartbleed SSL key exposure||Yes||Private/encrypted information exposure.|
ICS-CERT continues to reach out to the vendor community to bring awareness of the OpenSSL vulnerability (CVE-2014-0160). The following information is provided to assist the ICS community in making risk assessments of its environment to mitigate the threat of this exploit.
As part of DHS NCCIC, ICS-CERT is aware of reports of attempted exploitation and is in the process of confirming these reports. ICS-CERT continues to monitor the situation closely and encourages entities to report any and all incidents regarding this vulnerability to DHS.
To date, the following noninclusive list of references are available for analysis:
OUT OF BOUNDS READa
A flaw in the implementation of OpenSSL (Ver. 1.0.1 to 1.0.1f, and 1.0.2-beta1) could allow the private key used in SSL to be exposed. An attacker could then decrypt and read any secure data passed on the network link.
The vulnerability exists in the Heartbeat extension (RFC6520) to OpenSSL’s TLS and the DTLS protocols. The Heartbeat extension is functionally a “keep-alive” between end-users and the secure server. It works by sending periodic “data pulses” of 64 KB in size to the secure server and once the server receives that data; it reciprocates by resending the same data at the same size.d
The out-of-bounds “read” vulnerability exists because the Heartbeat extension does not properly validate the data being sent from the end-user. As a result, a malicious actor could send a specially crafted heartbeat request to the vulnerable server and obtain sensitive information stored in memory on the server. Furthermore, even though each heartbeat only allows requests to have a data size limited to 64 KB segments, it is possible to send repeated requests to retrieve more 64 KB segments, which could include encryption keys used for certificates, passwords, usernames, and even sensitive content that were stored at the time. An attacker could harvest enough data from the 64 KB segments to piece together larger groupings of information, which could help an attacker develop a broader understanding of the information being acquired.e
The following OpenSSL libraries are affected:
- OpenSSL Versions 1.0.1 through 1.0.1f and 1.0.2-beta1
The following ICS vendor products and versions are affected. See the advisory links for additional information such as how to obtain the available patches/upgrades:
--------- Begin Update F Part 1 of 1 --------
- Relion 650 series Ver. 1.3.0 (Patched)
--------- End Update F Part 1 of 1 --------
- atvise scada v2.3.x (Windows only - patched),
- atvise scada v2.4.x (Windows only - patched), and
- atvise scada v2.5.0 and v2.5.1 (Windows only - patched).
Digi – ICS-CERT advisory coming soon. Vendor notification at the following location: http://www.digi.com/support/kbase/kbaseresultdetl?id=3564
- ConnectPort LTS (update available),
- ConnectPort X2e (update available),
- Digi Embedded Linux (update available), and
- Wireless Vehicle Bus Adapter (update available).
- mGuard firmware Versions 8.0.0 and 8.0.1 (patched),
- mGuard firmware versions prior to 8.0.0 whether running on Innominate, Phoenix Contact, or other brands of devices are NOT affected.
- eLAN-8.2 eLAN prior to 8.3.3 (affected when RIP is used - update available),
- WinCC OA only V3.12 (always affected - update available),
- S7-1500 V1.5 (affected when HTTPS active),
- CP1543-1 V1.1 (affected when FTPS active), and
- APE 2.0 (affected when SSL/TLS component is used in customer implementation).
The following ICS products are not affected by this OpenSSL vulnerability:
- Cloud Connector by Etherios
- Connect WAN, WAN 3G
- ConnectPort X2, X4, X4H, X5
- ConnectPort WAN
- Device Cloud by Etherios
- Digi CM
- Digi Passport
- PortServer TS
- AnywhereUSB all models (updated 4/18/2014)
- The Social Machine by Etherios
- TransPort WR11, WR21, WR41, WR44
Garrettcom Magnum 6K Product Family (Unaffected OpenSSL version used)
Garrettcom Magnum 10K Product Family (Unaffected OpenSSL version used)
Garrettcom Magnum 12KX Product Family (Unaffected OpenSSL version used)
Garrettcom DS Product Family (Unaffected OpenSSL version used)
Garrettcom DX Product Family (Unaffected OpenSSL version used)
Garrettcom 10RX Product Family (Unaffected OpenSSL version used)
Hirschmann HiSecOS (Unaffected OpenSSL version used)
- Eagle20-400 and Eagle30-402
Hirschmann HiOS (Unaffected OpenSSL version used)
- RSPx, MSP, Embedded Switches
- All OEM products
Hirschmann HiLCOS (OpenSSL not used)
- BAT, OpenBAT, BAT Controller
- All OEM products
Hirschmann Switch Software Classic (Unaffected OpenSSL version used)
- EAGLE20, EagleOne
- All OEM products
Hirschmann BAT-C (OpenSSL not used)
Hirschmann Firewall Software mGuard (Unaffected OpenSSL version used)
- EAGLE mGuard
- All OEM products
Hirschmann IOLAN (Unaffected OpenSSL version used)
Hirschmann FMN alpha DSL, UMTS (Unaffected OpenSSL version used)
Hirschmann Industrial HiVision, HiVision (OpenSSL not used)
Hirschmann HiMobile, HiView (OpenSSL not used)
Tofino Security Versions 1.0 – 1.7 (Unaffected OpenSSL version used)
- MTL 9211ET
- Tofino Argon100/220, Eagle Tofino
- Schneider ConneXium Tofino
- Honeywell HMTF/HMRF/HOWF
- Invensys Triconex Tofino Firewall
- Solar Turbines STRCF
Tofino Security CMP all versions (OpenSSL not used)
Tofino Security Xenon Version 2.0.X (Unaffected OpenSSL version used; SSL/TLS components not used)
Tofino Security TC all versions (OpenSSL not used)
ICS-CERT encourages any asset owners/operators, developers, or vendors to coordinate known implementations of the affected products directly with ICS-CERT.
As OpenSSL may be used as a third-party component, asset owners, operators, and SCADA software developers are encouraged to investigate the use of the affected versions of OpenSSL in their environments.
OpenSSL Version 1.0.1g has addressed and mitigates this vulnerability. Please contact your software vendor to check for availability of updates. Any system that may be affected by this vulnerability should regenerate any credential information (secret keys, passwords, etc.) with the assumption that an attacker has already used this vulnerability to obtain those items.
Older versions of OpenSSL may not be vulnerable to the Heartbleed attacks, but have other known vulnerabilities that could be exploited. ICS-CERT strongly suggests that asset owners and operators verify what versions are running in the products being used in their facilities and then reference the following web site to determine which patched versions of OpenSSL should be used for the most secure operation. If there are still questions about what version is being used, contact the product vendor for verification.
Upgrade affected TLS/TDLS clients and servers to OpenSSL version 1.0.1g. Alternatively, affected versions of OpenSSL may be recompiled with the option
“-DOPENSSL_NO_HEARTBEATS” to mitigate the vulnerability until an upgrade can be performed.
Contact equipment vendors for specific mitigation information as the implementations may vary. In addition, IDS signatures are available that may provide awareness of an attack of this nature occurring. An example of these rule sets can be found heref:
alert tcp any [!80,!445] -> any [!80,!445] (msg:"FOX-SRT - Suspicious - SSLv3 Large Heartbeat Response"; flow:established,to_client; content:"|18 03 00|"; depth: 3; byte_test:2, >, 200, 3, big; byte_test:2, <, 16385, 3, big; threshold:type limit, track by_src, count 1, seconds 600; reference:cve,2014-0160; classtype:bad-unknown; sid: 1000000; rev:4;)
Additional Snort signatures have been provided by the FBI, “Mitigation against Open Secure Socket Layer Heartbeat Extension Vulnerability” at http://ics-cert.us-cert.gov/UPDATE-FBI-Snort-Signatures-Heartbleed-April-2014.
Snort community rules can be found at http://www.snort.org/snort-rules/#community.
Additional indicators of compromise are available on the Control Systems compartment of the US-CERT secure portal for owners and operators of critical infrastructure.
ICS-CERT encourages U.S. asset owners and operators to join the Control Systems compartment of the US-CERT secure portal. Send your name, e-mail address, and company affiliation to firstname.lastname@example.org.
NOTE: ICS-CERT has not tested the validity or efficacy of these rule sets and cautions users to thoroughly test these solutions before implementing them into production environments.
USE OF SPECIALIZED SEARCH ENGINES
Even prior to the discovery of the OpenSSL vulnerability, Internet facing devices have been a serious concern over the past few years with remote access demands giving way to insecure or vulnerable configurations. Tools such as SHODAN, Google, and other search engines enable researchers and adversaries to easily discover and identify a variety of ICS devices that were not intended to be Internet facing. This is due in part to ICS terminology and search terms that have become widely available because of an increasing public body of knowledge with detailed ICS information. Adding to the threat landscape is SHODAN’s linkages to exploit databases as well as continuous scanning and cataloguing of devices with emerging vulnerabilities such as DNP3 and OpenSSL. The availability of public information coupled with the aforementioned tools, lowers the level of knowledge required to successfully locate Internet facing control systems. In many cases, these devices have not been configured with adequate authentication mechanisms, thereby further increasing the chances of both opportunistic and targeted attempts to directly access these components.
Tools such as SHODAN may be proactively used by owners, operators, and security personnel to audit their networks and devices to locate Internet facing control system devices that may be susceptible to compromise. Asset owners are encouraged to query various search engines using the vendor product, model, and version of a device, to determine if their IP address block is found within the search results. If control systems devices are found using these tools, asset owners should take the necessary steps to remove these devices from direct or unsecured Internet access as soon as possible.
As tools and adversary capabilities advance, ICS-CERT expects that exposed systems will be more effectively discovered, and targeted. It has become more important than ever for asset owners and operators to audit their network configurations and properly install their ICS devices behind patched VPNs or firewalls.
ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:
- Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
- Locate control system networks and devices behind firewalls, and isolate them from the business network.
ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.
ICS-CERT also provides a recommended practices section for control systems on the ICS-CERT web site (http://ics-cert.us-cert.gov). Several recommended practices are available for reading or download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Organizations that observe any suspected malicious activity should follow their established internal procedures and report their findings to ICS-CERT for tracking and correlation against other incidents.
- a. CWE-125: Out of Bounds Read, https://cwe.mitre.org/data/definitions/125.html, web site last accessed April 12, 2014.
- b. CVE, http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0160, web site last accessed April 12, 2014.
- c. NVD, http://nvd.nist.gov/cvss.cfm?version=2&vector=AV:N/AC:L/Au:N/C:P/I:P/A:N), web site last accessed April 12, 2014.
- d. CVE, https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0160, web site last accessed April 12, 2014.
- e. SANS OpenSSL Vulnerability, http://digital-forensics.sans.org/blog/2014/04/10/heartbleed-links-simulcast-etc/, web site last accessed April 12, 2014.
- f. IDS signature examples, http://blog.fox-it.com/2014/04/08/openssl-heartbleed-bug-live-blog/, web site last accessed April 12, 2014.
For any questions related to this report, please contact the CISA at:
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