CVE-2021-38244 : Exploit Details and Defense Strategies

A regular expression denial of service (ReDoS) vulnerability exists in cbioportal 3.6.21 and older versions through a POST request to /ProteinArraySignificanceTest.json.

Understanding CVE-2021-38244

This CVE identifies a ReDoS vulnerability present in cbioportal versions 3.6.21 and below.

What is CVE-2021-38244?

The CVE-2021-38244 refers to a ReDoS vulnerability found in older versions of cbioportal, specifically version 3.6.21 and earlier. This vulnerability can be exploited through a POST request to /ProteinArraySignificanceTest.json.

The Impact of CVE-2021-38244

The vulnerability poses a risk of denial of service (DoS) attack due to inefficient regular expressions processing, potentially leading to service disruption or unresponsiveness.

Technical Details of CVE-2021-38244

Below are the technical details of the CVE:

Vulnerability Description

The vulnerability arises from improper input validation in processing regular expressions, allowing malicious actors to craft input triggering excessive backtracking and causing a DoS condition.

Affected Systems and Versions

Versions of cbioportal up to and including 3.6.21 are affected by this vulnerability. Users are advised to update to a patched version promptly.

Exploitation Mechanism

Exploitation of this vulnerability involves sending a specially crafted POST request to the /ProteinArraySignificanceTest.json endpoint, causing the server to perform excessive backtracking.

Mitigation and Prevention

To protect against CVE-2021-38244, follow these security measures:

Immediate Steps to Take

Upgrade cbioportal to the latest version to mitigate the vulnerability.
Monitor incoming POST requests to detect any potentially malicious activity.

Long-Term Security Practices

Regularly update and patch software to address known vulnerabilities.
Implement input validation mechanisms to prevent ReDoS vulnerabilities.

Patching and Updates

Vendor-provided patches or updates should be promptly applied to secure the cbioportal installation against this vulnerability.