CVE-2021-22897 : Vulnerability Insights and Analysis

This article provides detailed information about CVE-2021-22897, a vulnerability in curl versions 7.61.0 through 7.76.1 that exposes data to the wrong session due to an error in the code for CURLOPT_SSL_CIPHER_LIST when libcurl uses the Schannel TLS library.

Understanding CVE-2021-22897

CVE-2021-22897 is a vulnerability in the curl library that affects versions 7.61.0 through 7.76.1, leading to an exposure of data to the wrong session.

What is CVE-2021-22897?

curl 7.61.0 through 7.76.1 is impacted by a data exposure vulnerability caused by a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built using the Schannel TLS library. This flaw allows the last application to set ciphers to control the set used by all transfers, weakening transport security.

The Impact of CVE-2021-22897

The vulnerability in curl can significantly compromise transport security, allowing an attacker to potentially access sensitive data being transferred over the network.

Technical Details of CVE-2021-22897

This section covers the technical aspects of CVE-2021-22897, including the vulnerability description, affected systems, and the exploitation mechanism.

Vulnerability Description

curl 7.61.0 through 7.76.1 suffers from exposure of data element to the wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library.

Affected Systems and Versions

curl versions 7.61.0 through 7.76.1 are affected by this vulnerability.

Exploitation Mechanism

The vulnerability arises from how the selected cipher set is stored in a static variable, allowing the last transfer to set ciphers to control the set used by all transfers.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-22897, it is crucial to take immediate steps, adopt long-term security practices, and ensure timely patching and updates.

Immediate Steps to Take

System administrators and users should update curl to a non-vulnerable version and review network configurations to minimize exposure.

Long-Term Security Practices

Implement secure coding practices, conduct regular security audits, and train personnel on identifying and addressing security vulnerabilities.

Patching and Updates

Regularly check for security advisories and apply patches provided by curl to address CVE-2021-22897 and other security issues.