Adobe Acrobat Reader Acrord32.dll Use After Free Vulnerability

Advisory ID Internal

1. Advisory Information

Title: Adobe Acrobat Reader Acrord32.dll Use After Free Vulnerability
Advisory Id: CORE-2010-0701
Advisory URL:
Date published: 2010-10-05
Date of last update: 2010-10-05
Vendors contacted: Adobe
Release mode: Coordinated release

2. Vulnerability Information

Class: Use after free [CWE-416]
Impact: Code execution
Remotely Exploitable: Yes (client-side)
Locally Exploitable: No
CVE Name: CVE-2010-3627
Bugtraq ID: N/A

3. Vulnerability Description

Adobe Acrobat Reader is prone to a use-after-free vulnerability due to an invalid usage of a released memory chunk. This vulnerability could be used by a remote attacker to execute arbitrary code, by enticing the user of Adobe Acrobat Reader to open a specially crafted file and click on PAGES thumbnails.

4. Vulnerable packages

  • Adobe Acrobat Reader 9.x

5. Non-vulnerable packages

  • Adobe Acrobat Reader 8.x

6. Solutions and Workarounds

For further information about this issue look at the Adobe Security Bulletin and security blogs:

7. Credits

This vulnerability was discovered and researched by Ricardo Narvaja, from Core Security Technologies. This publication was coordinated by Fernando Russ.

8. Technical Description

Adobe Acrobat Reader is prone to a use-after-free vulnerability due to an invalid usage of a released memory chunk. A specially crafted .pdf file containing special flash code triggers an ACCESS_VIOLATION reading at address 0x00000030.

A more careful analysis of that code indicates that ESI points to a released chunk of memory. Exploitation is feasible forcing the allocation process of Adobe Acrobat Reader to reuse the chunk pointed by ESI with specially controlled data.

00EE10F8 MOV ECX,DWORD PTR DS:[ESI+1C] <-- ESI points to a previously released memory chunk. 00EE10FB MOV DWORD PTR SS:[EBP+78],EAX 00EE10FE MOV EAX,DWORD PTR DS:[ESI+18] 00EE1101 PUSH EAX 00EE1102 CALL DWORD PTR DS:[ECX+30] <-- The execution flow depends on the content of ECX. (ECX dependes on ESI) 

The content of the CPU register while an ACCESS_VIOLATION reading was triggered at 0x00EE1102,

 EAX 00000000 ECX 00000000 EDX 014D0A40 EBX 00000000 ESP 0013F1BC EBP 0013F24C ESI 02D5782C EDI 10A7C3D0 EIP 00EE1102 

This vulnerability could result in arbitrary code execution, although it was not verified.

9. Report Timeline

  • 2010-07-05: Core Security Technologies notifies the Adobe team of the vulnerability and announces its initial plan to publish the advisory on July 26th, 2010. A Proof of Concept (PoC) was sent to Adobe team.
  • 2010-07-06: Adobe team acknowledges Core Security Technologies' e-mail. Vendor also notifies that their world-wide offices will be shut down from July 5th to July 11th, and it may take a bit longer than usual to investigate this issue.
  • 2010-07-22: Core asks for a status update about this issue.
  • 2010-07-22: Adobe team notifies that they have reproduced the issue and expect the fix to be available in the next quarterly security update for Acrobat and Adobe Reader. These fixes are currently scheduled for an October patch Tuesday release.
  • 2010-07-26: Core notifies that the publication date for this advisory was re-scheduled to October 12th, 2010.
  • 2010-07-27: Core notifies that the publication date of October 12th, 2010 should be considered as final. If Adobe team does not release a patch on that day, Core will be forced to release this advisory in user-release mode.
  • 2010-09-28: Core notifies that the publication date of October 12th, 2010 is still valid and asks for a status update.
  • 2010-09-29: Adobe acknowledges the communication by informing that the publication date was re-scheduled to October 5th, 2010.
  • 2010-10-04: Core asks if the Adobe team has an assigned CVE identifier for this vulnerability and which are the affected versions of Adobe Reader.
  • 2010-10-04: Adobe notifies that:
    • This issue affects Reader 9.x, but not Reader 8.x.
    • The assigned identifier for this vulnerability is CVE-2010-3627.
  • 2010-10-05: Core publishes advisory CORE-2010-0701.

10. About CoreLabs

CoreLabs, the research center of Core Security Technologies, is charged with anticipating the future needs and requirements for information security technologies. We conduct our research in several important areas of computer security including system vulnerabilities, cyber attack planning and simulation, source code auditing, and cryptography. Our results include problem formalization, identification of vulnerabilities, novel solutions and prototypes for new technologies. CoreLabs regularly publishes security advisories, technical papers, project information and shared software tools for public use at:

11. About Core Security Technologies

Core Security Technologies develops strategic solutions that help security-conscious organizations worldwide develop and maintain a proactive process for securing their networks. The company's flagship product, CORE IMPACT, is the most comprehensive product for performing enterprise security assurance testing. CORE IMPACT evaluates network, endpoint and end-user vulnerabilities and identifies what resources are exposed. It enables organizations to determine if current security investments are detecting and preventing attacks. Core Security Technologies augments its leading technology solution with world-class security consulting services, including penetration testing and software security auditing. Based in Boston, MA and Buenos Aires, Argentina, Core Security Technologies can be reached at 617-399-6980 or on the Web at

12. Disclaimer

The contents of this advisory are copyright (c) 2010 Core Security Technologies and (c) 2010 CoreLabs, and are licensed under a Creative Commons Attribution Non-Commercial Share-Alike 3.0 (United States) License:

13. PGP/GPG Keys

This advisory has been signed with the GPG key of Core Security Technologies advisories team.