CVE-2021-29059 : Exploit Details and Defense Strategies

A vulnerability was discovered in IS-SVG version 2.1.0 to 4.2.2 and below, leading to a Regular Expression Denial of Service (ReDOS) vulnerability when the application processes a malicious SVG string.

Understanding CVE-2021-29059

This CVE refers to a vulnerability found in IS-SVG versions 2.1.0 to 4.2.2 and below that can be exploited to trigger a Regular Expression Denial of Service (ReDOS) by providing a specially crafted invalid SVG string.

What is CVE-2021-29059?

CVE-2021-29059 is a security vulnerability that exists in the IS-SVG library versions 2.1.0 to 4.2.2 and earlier. The issue arises when the application attempts to validate and process a malicious SVG string, potentially leading to a ReDOS attack.

The Impact of CVE-2021-29059

Exploitation of this vulnerability could result in a denial of service condition, causing affected systems to become unresponsive or crash. Attackers may leverage this weakness to disrupt the availability of services relying on the IS-SVG library.

Technical Details of CVE-2021-29059

This section provides an in-depth look into the technical aspects of CVE-2021-29059.

Vulnerability Description

The vulnerability allows threat actors to conduct a ReDOS attack by submitting a specifically crafted invalid SVG string to the IS-SVG library, leading to excessive CPU consumption and potential denial of service.

Affected Systems and Versions

IS-SVG versions 2.1.0 to 4.2.2 and earlier are affected by this vulnerability. Applications utilizing these versions are at risk of exploitation unless appropriate security measures are implemented.

Exploitation Mechanism

By submitting a carefully constructed malicious SVG string to the vulnerable IS-SVG library, attackers can trigger a ReDOS scenario, utilizing regular expressions to cause extended processing times and resource exhaustion.

Mitigation and Prevention

Protecting systems from CVE-2021-29059 involves proactive security measures and timely updates to address the vulnerability.

Immediate Steps to Take

Update to a patched version of IS-SVG, such as version 4.3.0 or later to mitigate the vulnerability.
Validate input data rigorously to prevent malicious SVG strings from triggering the ReDOS vulnerability.

Long-Term Security Practices

Regularly monitor security advisories for updates related to IS-SVG and other dependencies to stay informed about potential vulnerabilities.
Implement input validation mechanisms to filter out potentially harmful SVG strings and prevent ReDOS attacks.

Patching and Updates

Ensure your systems are up to date with the latest patches and security fixes provided by the IS-SVG library maintainers to protect against CVE-2021-29059.