CVE-2019-12760 : What You Need to Know

Parso version 0.4.0 and prior have a vulnerability in the way they handle grammar parsing from the cache, potentially leading to arbitrary code execution.

Understanding CVE-2019-12760

Parso version 0.4.0 and earlier are susceptible to a disputed deserialization vulnerability that could allow arbitrary code execution.

What is CVE-2019-12760?

Parso versions 0.4.0 and prior have a vulnerability in handling grammar parsing from the cache.
The flaw arises from the way cache loading relies on pickle, enabling the execution of arbitrary code if a malicious pickle is written to a cache grammar file and subsequently parsed.
There is a dispute regarding the severity of this vulnerability due to the typical lack of control by attackers over the cache directory in common configurations.

The Impact of CVE-2019-12760

The vulnerability could potentially allow attackers to execute arbitrary code on the affected system.
Exploitation of this flaw could lead to severe consequences, compromising the integrity and security of the system.

Technical Details of CVE-2019-12760

Parso version 0.4.0 and earlier are affected by a deserialization vulnerability that could result in arbitrary code execution.

Vulnerability Description

The vulnerability stems from the insecure handling of grammar parsing from the cache, allowing for the execution of arbitrary code.

Affected Systems and Versions

Parso versions 0.4.0 and prior are impacted by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting a malicious pickle and writing it to a cache grammar file, subsequently triggering its parsing.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks posed by CVE-2019-12760.

Immediate Steps to Take

Update Parso to a patched version that addresses the vulnerability.
Avoid loading untrusted grammar files from the cache.

Long-Term Security Practices

Regularly update software and libraries to the latest secure versions.
Implement secure coding practices to prevent similar vulnerabilities in the future.

Patching and Updates

Stay informed about security updates for Parso and promptly apply patches to secure the system.