CVE-2021-22898 : Security Advisory and Response

This article provides insights into CVE-2021-22898, a vulnerability impacting curl versions 7.7 through 7.76.1, leading to information disclosure when handling TELNET server communications.

Understanding CVE-2021-22898

CVE-2021-22898 is a security flaw in curl versions 7.7 through 7.76.1 that results in potential exposure of sensitive internal data when communicating with TELNET servers.

What is CVE-2021-22898?

curl 7.7 through 7.76.1 suffers from an information disclosure vulnerability due to an issue in the option parser for sending NEW_ENV variables. This flaw could allow uninitialized data from a stack-based buffer to be passed to the server, revealing internal information.

The Impact of CVE-2021-22898

The vulnerability could expose sensitive internal data to TELNET servers, posing a risk of information disclosure to malicious actors leveraging clear-text network protocols.

Technical Details of CVE-2021-22898

This section highlights specific technical aspects of the CVE-2021-22898 vulnerability.

Vulnerability Description

curl versions 7.7 through 7.76.1 are susceptible to an information disclosure flaw related to the handling of TELNET server communications.

Affected Systems and Versions

The vulnerability affects systems running curl versions 7.7 through 7.76.1.

Exploitation Mechanism

Exploiting this vulnerability involves manipulating the

-t

command line option, also known as

CURLOPT_TELNETOPTIONS

in libcurl, to send variable=content pairs to TELNET servers.

Mitigation and Prevention

Learn how to mitigate the risks associated with CVE-2021-22898 and secure affected systems.

Immediate Steps to Take

Users are advised to update curl to a patched version and avoid using the

-t

command line option when communicating with TELNET servers.

Long-Term Security Practices

Implement secure coding practices and stay informed about security updates from curl to prevent similar vulnerabilities.

Patching and Updates

Ensure that systems are regularly patched with the latest updates from curl to address CVE-2021-22898 and other security issues.