Vulnerabilities in SumatraPDF Reader Could Allow Arbitrary Code Execution

Executive Summary

Microsoft is providing notification of the discovery and remediation of multiple vulnerabilities affecting SumatraPDF Reader software version 2.0.1 and earlier. Microsoft discovered and disclosed the vulnerability under coordinated vulnerability disclosure to the affected vendor, SumatraPDF. SumatraPDF has remediated the vulnerabilities in their software.

Two vulnerabilities exist in the way that SumatraPDF Reader parses specially crafted PDF files. An attacker who successfully exploits either of these vulnerabilities could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Microsoft Vulnerability Research reported this issue to and coordinated with SumatraPDF to ensure remediation of this issue. These vulnerabilities have been assigned the entries, CVE-2012-4895 and CVE-2012-4896, in the Common Vulnerabilities and Exposures list. For more information, including information about updates from SumatraPDF, see the release notes for the project.

Mitigating Factors

• These vulnerabilities cannot be exploited automatically through email. For an attack to be successful, a user must open an attachment that is sent in an email message.
• In a web-based attack scenario, an attacker could host a website that contains a specially crafted file that is used to exploit these vulnerabilities. In addition, compromised websites and websites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit the vulnerabilities. In all cases, however, an attacker would have no way to force users to visit these websites. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message that takes users to the attacker’s website, and then convince them to open the specially crafted file.
• An attacker who successfully exploited either of these vulnerabilities could gain the same user rights as the current user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.