CVE-2021-4160 : What You Need to Know
Learn about CVE-2021-4160, a carry propagation bug in OpenSSL affecting MIPS platforms. Understand the impact, affected versions, and mitigation steps against this vulnerability.
A carry propagation bug in the MIPS32 and MIPS64 squaring procedure impacts several EC algorithms, including some default curves used in TLS 1.3 protocols.
Understanding CVE-2021-4160
This vulnerability affects OpenSSL versions 1.0.2, 1.1.1, and 3.0.0 on MIPS platforms, allowing for the potential generation of incorrect results.
What is CVE-2021-4160?
CVE-2021-4160 is a carry propagation bug in MIPS squaring procedures that affects several Elliptic Curve (EC) algorithms and TLS 1.3 default curves in OpenSSL. This issue arises due to the reuse of private keys, impacting the security of RSA, DSA, and DH mechanisms.
The Impact of CVE-2021-4160
While attacks against RSA and DSA are deemed very difficult to perform, a successful exploitation against DH is considered feasible, albeit challenging. The prerequisites for attacks are extensive resources and offline processing, making server configurations vulnerable only if sharing DH private keys among clients.
Technical Details of CVE-2021-4160
The vulnerability has been addressed in OpenSSL versions 1.0.2zc-dev, 1.1.1m, and 3.0.1. Affected versions include 1.0.2-1.0.2zb, 1.1.1-1.1.1l, and 3.0.0.
Vulnerability Description
A carry propagation issue in the MIPS architecture squaring procedure impacts various EC algorithms, potentially yielding incorrect cryptographic results.
Affected Systems and Versions
OpenSSL versions 1.0.2, 1.1.1, and 3.0.0 on MIPS platforms are susceptible to this vulnerability.
Exploitation Mechanism
The vulnerability could lead to attacks against DH if servers share DH private keys among multiple clients, although the execution is complex and resource-intensive.
Mitigation and Prevention
To mitigate the risks associated with CVE-2021-4160, immediate actions and long-term security practices are crucial.
Immediate Steps to Take
Users should update OpenSSL to the patched versions (1.0.2zc-dev, 1.1.1m, and 3.0.1) to address the vulnerability promptly.
Long-Term Security Practices
Implementing secure key management practices, regular security audits, and staying informed about security advisories can enhance overall system security.
Patching and Updates
Regularly applying security patches and updates provided by OpenSSL helps ensure that systems are protected against known vulnerabilities.