CVE-2019-13139 : Exploit Details and Defense Strategies

In Docker versions prior to 18.09.4, a vulnerability exists that allows an attacker to execute commands by manipulating the build path for the "docker build" command.

Understanding CVE-2019-13139

This CVE highlights a security issue in Docker versions before 18.09.4 that could lead to command execution by exploiting the way "docker build" handles remote git URLs.

What is CVE-2019-13139?

This vulnerability arises from a flaw in how "docker build" processes remote git URLs, enabling command injection into the "git clone" command, ultimately allowing code execution within the context of the user running the "docker build" command.

The Impact of CVE-2019-13139

The vulnerability could be exploited by an attacker with the ability to manipulate the build path for the "docker build" command, potentially leading to unauthorized command execution.

Technical Details of CVE-2019-13139

This section delves into the specific technical aspects of the CVE.

Vulnerability Description

The vulnerability in Docker versions prior to 18.09.4 allows for command injection into the "git clone" command, resulting in code execution due to the misinterpretation of git ref as a flag.

Affected Systems and Versions

Product: Docker
Vendor: Docker
Versions Affected: All versions prior to 18.09.4

Exploitation Mechanism

The vulnerability can be exploited by manipulating the build path for the "docker build" command, enabling unauthorized command execution.

Mitigation and Prevention

Protecting systems from CVE-2019-13139 requires immediate action and long-term security practices.

Immediate Steps to Take

Update Docker to version 18.09.4 or later to mitigate the vulnerability.
Avoid using untrusted build paths for the "docker build" command.

Long-Term Security Practices

Regularly monitor Docker security advisories and apply patches promptly.
Implement secure coding practices to prevent command injection vulnerabilities.

Patching and Updates

Stay informed about security updates from Docker and apply patches as soon as they are available.