CVE-2017-1000115 : What You Need to Know

Mercurial prior to version 4.3 is vulnerable to a missing symlink check that can allow malicious repositories to modify files outside the repository.

Understanding CVE-2017-1000115

Versions of Mercurial earlier than 4.3 contain a vulnerability where a lack of symlink verification allows malicious repositories to manipulate files beyond the boundaries of the repository.

What is CVE-2017-1000115?

This CVE refers to a security vulnerability in Mercurial versions prior to 4.3 that enables malicious repositories to manipulate files outside the repository due to a lack of symlink verification.

The Impact of CVE-2017-1000115

The vulnerability can be exploited by attackers to modify files beyond the repository's boundaries, potentially leading to unauthorized access or data manipulation.

Technical Details of CVE-2017-1000115

Mercurial prior to version 4.3 is susceptible to a symlink verification flaw that allows unauthorized file manipulation.

Vulnerability Description

The vulnerability arises from a lack of proper symlink verification, enabling malicious repositories to tamper with files located outside the repository's designated boundaries.

Affected Systems and Versions

Systems running Mercurial versions earlier than 4.3 are affected.

Exploitation Mechanism

Malicious repositories can exploit the vulnerability to manipulate files beyond the repository's intended scope.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of this vulnerability.

Immediate Steps to Take

Upgrade Mercurial to version 4.3 or later to mitigate the symlink verification issue.
Regularly monitor and audit repository activities for any unauthorized file modifications.

Long-Term Security Practices

Implement strict access controls and permissions to limit repository manipulation rights.
Educate users on secure coding practices and the risks associated with unverified symlinks.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by Mercurial to address known vulnerabilities.