Exemys Web Server Bypass Vulnerability


基本信息

时间: 2015-11-17

风险等级: 未知

ICSA: ICS Advisory (ICSA-15-321-01)

厂商: 未知

原地址: https://www.us-cert.gov/ics/advisories/ICSA-15-321-01


OVERVIEW

Independent researcher Maxim Rupp has identified a login bypass in the Exemys Telemetry Web Server. Exemys has not produced a patch to mitigate this vulnerability.

This vulnerability could be exploited remotely.

AFFECTED PRODUCTS

The following Exemys product is affected:

  • Exemys Telemetry Web Server.

IMPACT

This vulnerability can allow access to the server without proper login credentials.

Impact to individual organizations depends on many factors that are unique to each organization. NCCIC/ICS-CERT recommends that organizations evaluate the impact of this vulnerability based on their operational environment, architecture, and product implementation.

BACKGROUND

Exemys is an Argentina-based company that exports to the United States, Canada, Latin America, Asia, and Europe.

The affected product, Telemetry Web Server, is a web-based SCADA system. According to Exemys, Telemetry Web Servers are deployed across several sectors including Critical Manufacturing, Energy, Financial Services, Healthcare and Public Health, and Information Technology. Exemys estimates that these products are used primarily in the United States, Latin America, Europe, and Asia.

VULNERABILITY CHARACTERIZATION

VULNERABILITY OVERVIEW

AUTHENTICATION BYPASSa

The Exemys Telemetry Web Server allows the attacker to directly access the information by ignoring the location header.

CVE-2015-7910b has been assigned to this vulnerability. A CVSS v3 base score of 8.6 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N).c

VULNERABILITY DETAILS

EXPLOITABILITY

This vulnerability could be exploited remotely.

EXISTENCE OF EXPLOIT

No known public exploits specifically target this vulnerability.

DIFFICULTY

An attacker with a low skill would be able to exploit this vulnerability.

MITIGATION

ICS-CERT recommends implementing a single point login that cannot be bypassed.

ICS-CERT further 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 remote devices behind firewalls, and isolate them from the business network.
  • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

ICS-CERT reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

ICS-CERT also provides a section for control systems security recommended practices on the ICS-CERT web page at: http://ics-cert.us-cert.gov/content/recommended-practices. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available in the ICS‑CERT Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies, that is available for download from the ICS-CERT web site (http://ics-cert.us-cert.gov/).

Organizations observing 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-592:Authentication Bypass issues, http://cwe.mitre.org/data/definitions/592.html, web site last accessed November 17, 2015
  • b. NVD, http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-7910, NIST uses this advisory to create the CVE web site report. This web site will be active sometime after publication of this advisory
  • c. CVSS Calculator, https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N, web site last accessed November 17, 2015