-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 National Cyber Alert System Technical Cyber Security Alert TA09-051A Adobe Acrobat and Reader Vulnerability Original release date: February 20, 2009 Last revised: -- Source: US-CERT Systems Affected * Adobe Reader version 9 and earlier * Adobe Acrobat (Professional, 3D, and Standard) version 9 and earlier Overview Adobe has released Security Bulletin APSB09-01, which describes a vulnerability that affects Adobe Reader and Acrobat. This vulnerability could allow a remote attacker to execute arbitrary code. I. Description Adobe Security Bulletin APSB09-01 describes a memory-corruption vulnerability that affects Adobe Reader and Acrobat. Further details are available in Vulnerability Note VU#905281. An attacker could exploit these vulnerabilities by convincing a user to load a specially crafted Adobe Portable Document Format (PDF) file. Acrobat integrates with popular web browsers, and visiting a website is usually sufficient to cause Acrobat to load PDF content. II. Impact An attacker may be able to execute arbitrary code. III. Solution 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 and un-check Enable Acrobat JavaScript). 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 the safer option of prompting 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. Un-check the "Display PDF in browser" check box. Do not access PDF documents from untrusted sources Do not open unfamiliar or unexpected PDF documents, particularly those hosted on web sites or delivered as email attachments. Please see Cyber Security Tip ST04-010. IV. References * Adobe Security Bulletin apsa09-01 - * Securing Your Web Browser - * Vulnerability Note VU#905281 - ____________________________________________________________________ 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 "TA09-051A Feedback VU#905281" in the subject. ____________________________________________________________________ For instructions on subscribing to or unsubscribing from this mailing list, visit . ____________________________________________________________________ Produced 2009 by US-CERT, a government organization. Terms of use: ____________________________________________________________________ Revision History February 20, 2009: Initial release -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iQEVAwUBSZ8ayXIHljM+H4irAQIUcAf+M01pEVt0f1ZdRvCQwSYw1efnHu4YGdhI xT27jeKvaW/h6ghGx0L9YWCSn/A2LY3D+fDU1PZmWi7TT/SMEQ8LvKomyCu026Dv fD63qIXYj3NoPu11bINKFX4HFQCOYWKuM/58Y8mDQXOg0RLhePfMhMbB/S5/xpNT J09FupEgMvbD+tjVILP+W8JSY4YtAxUJLHfB7cTTHGtlKZyAsnnmJM3Oi4au10DW vqZD8JefoMLeV2MTGRyP4HGTaRxVY1+yucXO1KBGnKX7otCRkCWOupEuKw+tIEkT YsYIlkH5MzftkesSEDpDMIAiIE+uprJRv2HGkc38Rhbs/03JyxxVlA== =HSro -----END PGP SIGNATURE-----