-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 National Cyber Alert System Technical Cyber Security Alert TA10-103C Adobe Reader and Acrobat Vulnerabilities Original release date: April 13, 2010 Last revised: -- Source: US-CERT Systems Affected * Adobe Reader 9.3.1 and earlier 9.x versions * Adobe Reader 8.2.1 and earlier versions * Adobe Acrobat 9.3.1 and earlier 9.x versions * Adobe Acrobat 8.2.1 and earlier versions Overview Adobe has released Security Bulletin APSB10-09, which describes multiple vulnerabilities affecting Adobe Reader and Acrobat. I. Description Adobe Security Bulletin APSB10-09 describes a number of vulnerabilities affecting Adobe Reader and Acrobat. These vulnerabilities affect Reader and Acrobat 9.3.1 and earlier 9.x versions, and 8.2.1 and earlier versions. An attacker could exploit these vulnerabilities by convincing a user to open a specially crafted PDF file. The Adobe Reader browser plug-in is available for multiple web browsers and operating systems, which can automatically open PDF documents hosted on a website. II. Impact These vulnerabilities could allow a remote attacker to execute arbitrary code, write arbitrary files or folders to the file system, escalate local privileges, or cause a denial of service on an affected system as the result of a user opening a malicious PDF document. III. Solution Update Adobe has released updates to address this issue. Users are encouraged to read Adobe Security Bulletin APSB10-09 and update vulnerable versions of Adobe Reader and Acrobat. Adobe does not offer standalone installers of Reader or Acrobat versions 9.3.2 or 8.2.2. For a fresh installation, first install Adobe Reader 9.3.0 or 8.2.0 and then use the automatic update feature or install the appropriate update referenced in APSB10-09. Disable JavaScript in Adobe Reader and Acrobat Disabling JavaScript may prevent some exploits from resulting in code execution. Acrobat JavaScript can be disabled using the Preferences menu (Edit -> Preferences -> JavaScript; uncheck Enable Acrobat JavaScript). Adobe provides a framework to blacklist specific JavaScipt APIs. If JavaScript must be enabled, this feature may be useful when specific APIs are known to be vulnerable or used in attacks. Prevent Internet Explorer from automatically opening PDF documents The installer for Adobe Reader and Acrobat configures Internet Explorer to automatically open PDF files without any user interaction. This behavior can be reverted to a safer option that prompts the user by importing the following as a .REG file: Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT\AcroExch.Document.7] "EditFlags"=hex:00,00,00,00 Disable the display of PDF documents in the web browser Preventing PDF documents from opening inside a web browser will partially mitigate this vulnerability. If this workaround is applied, it may also mitigate future vulnerabilities. To prevent PDF documents from automatically being opened in a web browser, do the following: 1. Open Adobe Acrobat Reader. 2. Open the Edit menu. 3. Choose the Preferences option. 4. Choose the Internet section. 5. Uncheck the "Display PDF in browser" checkbox. Do not access PDF documents from untrusted sources Do not open unfamiliar or unexpected PDF documents, particularly those hosted on websites or delivered as email attachments. Please see Cyber Security Tip ST04-010. IV. References * Security update available for Adobe Reader and Acrobat - * Upcoming Adobe Reader and Acrobat 9.3.2 and 8.2.2 to be Delivered by New Updater - * Adobe Reader and Acrobat JavaScript Blacklist Framework - ____________________________________________________________________ The most recent version of this document can be found at: ____________________________________________________________________ Feedback can be directed to US-CERT Technical Staff. Please send email to with "TA10-103C Feedback VU#352598" in the subject. ____________________________________________________________________ For instructions on subscribing to or unsubscribing from this mailing list, visit . ____________________________________________________________________ Produced 2010 by US-CERT, a government organization. Terms of use: ____________________________________________________________________ Revision History April 13, 2010: Initial release -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iQEVAwUBS8TuRj6pPKYJORa3AQJfzggAj8p3s/TrJT16ceFtRzLR31QBgRq6GxYr h8WnsGlj2WR71XjH219XaWx9Mj3KBWVxbAsNPmK0tEir7KA+n4DwZCewTDYRqfYs 8N7G9MOI68Z87+7zBiZAo0j5/lQuxLWyTF9PqWbX8gCWLqJWW46cEZCqg7OGRbYt w8coxdMXU6tM3WGoWAIKwLRtpQUdubcITPTrE7RATyLJ1422B9dkTSeSCuHHZs5d eXSPYzTQ1EOwHpuA5/a/or2SjeRPLQcpxb/8WKelSqwW3hpK4zviEnPt4cYyeNqW BQY06OQMTKch/nmniuEDuiwe69m0gTw7Tw2Dm6xrg6BLBy3A6GAwkQ== =CQ6i -----END PGP SIGNATURE-----