VideoLAN VLC Core Audio Format Files Denial of Service Vulnerability [CVE-2018-19857 ]
CVE Number – CVE-2018-19857
A vulnerability in VideoLAN VLC could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.
The vulnerability is due to improper handling of magic cookies in Core Audio Format (CAF) files, which could result in an uninitialized memory read in the CAF demuxer. The CAF demuxer is defined in the modules/demux/caf.c source code file of the affected software. The uninitialized memory read in the CAF demuxer is caused by a typecast that converts a possibly negative return value to an unsigned integer in the ReadKukiChunk() function. An attacker could exploit this vulnerability by persuading a user to access a CAF file that submits malicious input to the targeted system. An exploit could cause a DoS condition or possibly allow the attacker to access sensitive information.
Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.
VideoLAN has confirmed the vulnerability and released software updates.
Analysis
- To exploit this vulnerability, an attacker may persuade a user to access a CAF file that submits malicious input to the targeted system by using misleading language and instructions.
Safeguards
- Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.
Administrators are advised to use an unprivileged account when browsing the Internet.
Administrators are advised to monitor critical systems.
Vendor Announcements
- VideoLAN has released a git commit at the following link: commit 0cc5ea748ee5ff7705dde61ab15dff8f58be39d0
Fixed Software
- VideoLAN has released a software patch at the following link: caf: fix integer underflow
Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.