CIS CYBERSECURITY ADVISORIES

MS-ISAC ADVISORY NUMBER:
2015-063

DATE(S) ISSUED:
06/09/2015

SUBJECT:
Cumulative Security Update for Internet Explorer (MS15-056)

OVERVIEW:

Multiple vulnerabilities have been discovered in Microsoft's web browser, Internet Explorer, which could allow an attacker to take complete control of an affected system. Successful exploitation of these vulnerabilities could result in an attacker gaining elevated privileges on the system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

THREAT INTELLIGENCE:

There is no known proof-of-concept code available at this time. Updates are available.

SYSTEMS AFFECTED:

  • Internet Explorer 6
  • Internet Explorer 7
  • Internet Explorer 8
  • Internet Explorer 9
  • Internet Explorer 10
  • Internet Explorer 11

RISK:

Government:

  • Small government entities:High
  • Large and medium government entities: High

Businesses:

  • Large and medium business entities:High
  • Small business entities:High

Home users: High

TECHNICAL SUMMARY:

Multiple vulnerabilities were discovered in Internet Explorer due to the way objects in memory are improperly accessed. The vulnerabilities are as follows:

  • 20 Memory Corruption Vulnerabilities (CVE-2015-1687, CVE-2015-1730, CVE-2015-1731, CVE-2015-1732, CVE-2015-1735, CVE-2015-1736, CVE-2015-1737, CVE-2015-1740, CVE-2015-1741, CVE-2015-1742, CVE-2015-1744, CVE-2015-1745, CVE-2015-1747, CVE-2015-1750, CVE-2015-1751, CVE-2015-1752, CVE-2015-1753, CVE-2015-1754, CVE-2015-1755, CVE-2015-1766)
  • Three Escalation Privilege Vulnerabilities (CVE-2015-1739, CVE-2015-1743, CVE-2015-1748)
  • One Information Disclosure Vulnerability (CVE-2015-1765)

These vulnerabilities could allow an attacker to execute remote code by luring a victim to a malicious website. When the website is visited, the attacker's script will run with same permissions as the affected user account. Successful exploitation of these vulnerabilities could result in an attacker gaining elevated privileges on the system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

RECOMMENDATIONS:

We recommend the following actions be taken:

  • Apply appropriate patches provided by Microsoft to vulnerable systems immediately after appropriate testing.
  • Run all software as a non-privileged user (one without administrative privileges) to diminish theeffects of a successful attack.
  • Remind users not to click links from unknown sources, or to click links without verifying the intended destination.

REFERENCES:

Microsoft:

https://technet.microsoft.com/library/security/MS15-056

CVE:

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1687

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1730

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1731

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1732

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1735

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1736

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1737

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1739

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1740

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1741

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1742

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1743

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1744

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1745

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1747

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1748

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1750

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1751

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1752

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1753

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1754

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1755

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1765

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1766