1. Advisory Information
Title: VLC Vulnerabilities handling .AMV and .NSV files
Advisory ID: CORE-2011-0208
Advisory URL: http://www.coresecurity.com/content/vlc-vulnerabil
Date published: 2011-03-23
Date of last update: 2011-03-23
Vendors contacted: VLC team
Release mode: Coordinated release
2. Vulnerability Information
Class: Buffer overflow [CWE-119], Buffer overflow [CWE-119]
Impact: Code execution
Remotely Exploitable: Yes (client-side)
Locally Exploitable: No
CVE Name: CVE-2010-3275, CVE-2010-3276
3. Vulnerability Description
Two vulnerabilities have been found in VLC media player [1], when handling .AMV and .NSV file formats. These vulnerabilities can be exploited by a remote attacker to obtain arbitrary code execution with the privileges of the user running VLC.
4. Vulnerable packages
- VLC 1.1.4
- VLC 1.1.5
- VLC 1.1.6
- VLC 1.1.7
- Older versions may be affected, but were not checked.
5. Non-vulnerable packages
- VLC 1.1.8
6. Vendor Information, Solutions and Workarounds
These vulnerabilities are fixed in VLC version 1.1.8, which can be downloaded from http://www.videolan.org/
7. Credits
These vulnerabilities were discovered and researched by Ricardo Narvaja from Core Security Technologies. Publication was coordinated by Carlos Sarraute.
8. Technical Description / Proof of Concept Code
8.1. Vulnerability in VLC 1.1.4 to 1.1.7 when handling AMV files [CVE-2010-3275]
This vulnerability was found by fuzzing different formats. In AMV files if the offset 0x41 is changed to a value greater than 90 as shown below:
[+ full code]Then the program will crash in the following plugin:
[+ full code]More precisely in this location:
[+ full code]When executing an appropriate heap spray in Internet explorer:
[+ full code]We manage to take control of the execution flow and execute our code:
[+ full code]8.2. Vulnerability in VLC 1.1.4 to 1.1.7 when handling NSV files [CVE-2010-3276]
In NSV files when changing the offsets 0x0b to 0x0e as shown below:
[+ full code]We can make the program crash in the following plugin:
[+ full code]More precisely in this location:
[+ full code]When executing an appropriate heap spray in Internet explorer:
[+ full code]We make the execution continue in our code:
[+ full code]9. Report Timeline
- 2011-02-08: Core Security Technologies notifies the VLC team of the vulnerabilities. Publication date is temporarily set to February 28, 2011.
- 2011-02-08: VLC team acknowledges notification and provides PGP keys.
- 2011-02-09: Core sends a technical description and PoC files that trigger the vulnerabilities.
- 2011-02-18: Core asks the VLC team whether they could reproduce the vulnerabilities.
- 2011-02-23: VLC team replies that fixes will be included in VLC 1.1.8, and that they believe the issue is not exploitable.
- 2011-02-25: Core replies that the issues have been confirmed to be exploitable, and that the researcher has developed fully working exploits. Core offers to reschedule the publication of its advisory to coordinate it with the release of fixes.
- 2011-03-10: Core requests an update on this issue, since no reply was received. Core notes that the PoC files and exploits were tested on Windows only, and reschedules publication to March 16, stating that the advisory will be published as "user release" if no reply is received.
- 2011-03-10: VLC team requests two additional weeks for the release of fixes, and asks whether the vulnerabilities are exploitable with ASLR.
- 2011-03-14: Core agrees to postpone publication, confirms that the bugs are exploitable with ASLR, and requests a concrete date for the release.
- 2011-03-16: VLC team states that they would like to release on March 23rd.
- 2011-03-18: Core agrees with the release date.
- 2011-03-23: Advisory CORE-2011-0208 is published.
10. References
[1] VLC media player http://www.videolan.org/
11. 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: http://corelabs.coresecurity.com.
12. About Core Security Technologies
Core Security Technologies enables organizations to get ahead of threats with security test and measurement solutions that continuously identify and prove real-world exposures to their most critical assets. Our customers can gain real visibility into their security standing, real validation of their security controls, and real metrics to more effectively secure their organizations.
Core Security's software solutions build on over a decade of trusted research and leading-edge threat expertise from the company's Security Consulting Services, CoreLabs and Engineering groups. Core Security Technologies can be reached at +1 (617) 399-6980 or on the Web at: http://www.coresecurity.com.
13. Disclaimer
The contents of this advisory are copyright (c) 2011 Core Security Technologies and (c) 2011 CoreLabs, and are licensed under a Creative Commons Attribution Non-Commercial Share-Alike 3.0 (United States) License: http://creativecommons.org/licenses/by-nc-sa/3.0/u
14. PGP/GPG Keys
This advisory has been signed with the GPG key of Core Security Technologies advisories team, which is available for download at http://www.coresecurity.com/files/attachments/core