CVE-2019-19911 Explained : Impact and Mitigation

Pillow version 6.2.2 and earlier have a vulnerability known as DoS (Denial of Service) due to a coding issue in FpxImagePlugin.py. This vulnerability can lead to various errors and process termination based on the Python version and operating system.

Understanding CVE-2019-19911

Pillow version 6.2.2 and earlier are susceptible to a Denial of Service vulnerability.

What is CVE-2019-19911?

The vulnerability in Pillow before version 6.2.2 is caused by improper validation in the range function, leading to potential DoS attacks.

The Impact of CVE-2019-19911

The vulnerability can result in different consequences based on the Python version and OS:

On 32-bit Python running on Windows: OverflowError or MemoryError due to the 2 GB limit.
On 64-bit Python running on Linux: Process termination by the OOM killer.

Technical Details of CVE-2019-19911

Pillow version 6.2.2 and earlier are affected by this vulnerability.

Vulnerability Description

The vulnerability arises from the code in FpxImagePlugin.py, where the range function is used on a 32-bit integer without proper validation if the number of bands is large.

Affected Systems and Versions

Pillow version 6.2.2 and earlier

Exploitation Mechanism

The vulnerability can be exploited by manipulating the number of bands in the image, triggering the range function without proper validation.

Mitigation and Prevention

To address CVE-2019-19911, consider the following steps:

Immediate Steps to Take

Update Pillow to version 6.2.2 or later to mitigate the vulnerability.
Monitor system resources for any unusual behavior that could indicate a DoS attack.

Long-Term Security Practices

Regularly update software and libraries to patch known vulnerabilities.
Implement proper input validation and error handling in code to prevent similar issues.

Patching and Updates

Apply patches provided by Pillow to fix the vulnerability and enhance system security.