Overview
Adobe Reader and Acrobat contain vulnerabilities in the customDictionaryOpen() and getAnnots() JavaScript methods.
Description
Adobe Reader and the Adobe Acrobat family of software is designed to create, view, and edit Portable Document Format (PDF) files. Adobe Reader is widely deployed, and the Acrobat Reader Plug-In displays PDF inside a web browser. Adobe Reader and Acrobat support JavaScript. The JavaScript methods customDictionaryOpen() (CVE-2009-1493) and getAnnots() (CVE-2009-1492) do not safely handle specially crafted arguments and can be manipulated to execute arbitrary code. Publicly available exploit code claims to work on Adobe Reader 9.1 and 8.1.4 on GNU/Linux. Limited testing shows that Adobe Reader and Acrobat on and Microsoft Windows platforms crash when parsing a PDF file that contains a specially crafted getAnnots() call. As of 2009-04-29 we have not confirmed the reported customDictionaryOpen() vulnerability. |
Impact
By convincing a user to open a specially crafted PDF file, an attacker may be able to execute arbitrary code. |
Solution
Update |
Some vendors ship JavaScript support in a separate package. Removing this package may remove JavaScript support. 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 displaying of PDF documents in the web browser Preventing PDF documents from opening inside a web browser reduces attack surface. If this workaround is applied to updated versions of Adobe Reader and Acrobat, it may protect against future vulnerabilities. To prevent PDF documents from automatically being opened in a web browser with Adobe Reader:
To disable the vulnerable getAnnots() method, rename or remove the Annots.api file. This will disable some Annotation functionality, however annotations can still be viewed. This does not protect against the customDictionaryOpen() vulnerability. On Windows, Annots.api is typically located here: "%ProgramFiles%\Adobe\Reader 9.0\Reader\plug_ins" Example location on GNU/Linux: /opt/Adobe/Reader8/Reader/intellinux/plug_ins/Annots.api 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. |
Vendor Information
CVSS Metrics
| Group | Score | Vector |
|---|---|---|
| Base | 0 | AV:--/AC:--/Au:--/C:--/I:--/A:-- |
| Temporal | 0 | E:Not Defined (ND)/RL:Not Defined (ND)/RC:Not Defined (ND) |
| Environmental | 0 | CDP:Not Defined (ND)/TD:Not Defined (ND)/CR:Not Defined (ND)/IR:Not Defined (ND)/AR:Not Defined (ND) |
References
- http://www.adobe.com/support/security/bulletins/apsb09-06.html
- http://www.adobe.com/support/security/advisories/apsa09-02.html
- http://blogs.adobe.com/psirt/2009/04/potential_adobe_reader_issue.html
- http://blogs.adobe.com/psirt/2009/04/update_on_adobe_reader_issue.html
- http://blogs.adobe.com/psirt/2009/05/adobe_reader_issue_update.html
- http://www.adobe.com/devnet/acrobat/pdfs/js_api_reference.pdf
- http://www.securityfocus.com/bid/34736/
- http://www.securityfocus.com/bid/34740/
Acknowledgements
These vulnerabilities were publicly reported by Arr1val.
This document was written by Art Manion.
Other Information
| CVE IDs: | CVE-2009-1492, CVE-2009-1493 |
| Severity Metric: | 21.80 |
| Date Public: | 2009-04-28 |
| Date First Published: | 2009-04-29 |
| Date Last Updated: | 2009-09-05 02:06 UTC |
| Document Revision: | 44 |