CVE-2018-20721 Explained : Impact and Mitigation

CVE-2018-20721, published on January 16, 2019, addresses a vulnerability in the uriparser library prior to version 0.9.1. The vulnerability involves an out-of-bounds read issue in the URI parsing functions when processing incomplete URIs with specific IPv6 and IPv4 address combinations.

Understanding CVE-2018-20721

This section delves into the details of the vulnerability and its impact.

What is CVE-2018-20721?

The function URI_FUNC() in UriParse.c within the uriparser library encounters an out-of-bounds read issue in the uriParseEx functions. This occurs when processing an incomplete URI that includes an IPv6 address with an embedded IPv4 address, such as "//[::44.1".

The Impact of CVE-2018-20721

The vulnerability can potentially lead to security breaches and unauthorized access to systems utilizing the affected uriparser library.

Technical Details of CVE-2018-20721

Explore the technical aspects of the CVE-2018-20721 vulnerability.

Vulnerability Description

The vulnerability in uriparser before version 0.9.1 results in an out-of-bounds read in the uriParseEx functions when handling incomplete URIs with specific address formats.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: All versions prior to 0.9.1

Exploitation Mechanism

The vulnerability is exploited by crafting incomplete URIs with IPv6 addresses containing embedded IPv4 addresses, triggering the out-of-bounds read in the parsing functions.

Mitigation and Prevention

Learn how to mitigate the risks associated with CVE-2018-20721.

Immediate Steps to Take

Update the uriparser library to version 0.9.1 or later to patch the vulnerability.
Monitor for any unauthorized access or unusual activities on systems.

Long-Term Security Practices

Regularly update software libraries and dependencies to prevent known vulnerabilities.
Conduct security assessments and audits to identify and address potential weaknesses.

Patching and Updates

Ensure timely application of security patches and updates to all software components to maintain a secure environment.