CVE-2020-10378 : Security Advisory and Response

In libImaging/PcxDecode.c in Pillow before 7.1.0, an out-of-bounds read can occur when reading PCX files where state->shuffle is instructed to read beyond state->buffer.

Understanding CVE-2020-10378

This CVE involves a vulnerability in Pillow before version 7.1.0 that can lead to an out-of-bounds read when processing PCX files.

What is CVE-2020-10378?

The vulnerability in libImaging/PcxDecode.c in Pillow before 7.1.0 allows for an out-of-bounds read during the processing of PCX files.

The Impact of CVE-2020-10378

The vulnerability could potentially be exploited by an attacker to read beyond the intended boundaries of the buffer, leading to information disclosure or a denial of service.

Technical Details of CVE-2020-10378

This section provides more in-depth technical information about the CVE.

Vulnerability Description

The issue arises from an out-of-bounds read in Pillow's processing of PCX files, specifically when state->shuffle extends beyond state->buffer.

Affected Systems and Versions

Product: n/a
Vendor: n/a
Versions affected: All versions before 7.1.0

Exploitation Mechanism

The vulnerability can be exploited by crafting a malicious PCX file that triggers the out-of-bounds read when processed by the vulnerable version of Pillow.

Mitigation and Prevention

To address CVE-2020-10378, consider the following mitigation strategies:

Immediate Steps to Take

Update Pillow to version 7.1.0 or later to mitigate the vulnerability.
Avoid opening PCX files from untrusted sources until the software is patched.

Long-Term Security Practices

Regularly update software and libraries to the latest versions to prevent known vulnerabilities.
Implement file type validation checks to ensure that only safe file formats are processed.

Patching and Updates

Apply patches and updates provided by the Pillow project to fix the vulnerability and enhance the security of the software.