CVE-2021-40528 : Security Advisory and Response

This CVE record describes a vulnerability in the ElGamal implementation in Libgcrypt before version 1.9.4, allowing plaintext recovery through a cross-configuration attack against OpenPGP.

Understanding CVE-2021-40528

This section provides an overview of the identified vulnerability.

What is CVE-2021-40528?

The ElGamal implementation in Libgcrypt before 1.9.4 is susceptible to plaintext recovery due to a specific dangerous combination involving the prime, generator, and ephemeral exponents, enabling a cross-configuration attack against OpenPGP.

The Impact of CVE-2021-40528

The vulnerability can lead to plaintext recovery, posing a security risk to systems utilizing the affected versions of Libgcrypt.

Technical Details of CVE-2021-40528

Explore the technical aspects of the CVE.

Vulnerability Description

The vulnerability in the ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery by exploiting a certain combination of cryptographic parameters.

Affected Systems and Versions

Vendor: Not applicable
Product: Not applicable
Versions: All versions prior to Libgcrypt 1.9.4 are impacted.

Exploitation Mechanism

The vulnerability arises from an unsafe combination of the prime, generator, and ephemeral exponents in the context of cryptographic operations, facilitating plaintext recovery and potential attacks.

Mitigation and Prevention

Learn how to address the CVE and enhance security measures.

Immediate Steps to Take

Update Libgcrypt to version 1.9.4 or above to mitigate the vulnerability.
Consider implementing additional encryption measures to safeguard sensitive data.

Long-Term Security Practices

Regularly monitor security advisories and apply patches promptly.
Conduct thorough security assessments to identify and address potential vulnerabilities.

Patching and Updates

Stay informed about security updates from Libgcrypt and promptly apply patches to secure systems and data.