CVE-2022-35409 : Exploit Details and Defense Strategies
Discover the impact and technical details of CVE-2022-35409, a heap-based buffer over-read vulnerability in Mbed TLS versions before 2.28.1 and 3.x before 3.2.0, allowing unauthenticated attackers to trigger server crashes.
An issue was discovered in Mbed TLS before 2.28.1 and 3.x before 3.2.0. In some configurations, an unauthenticated attacker can send an invalid ClientHello message to a DTLS server that causes a heap-based buffer over-read of up to 255 bytes. This can cause a server crash or possibly information disclosure based on error responses. Affected configurations have MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE enabled and MBEDTLS_SSL_IN_CONTENT_LEN less than a threshold that depends on the configuration: 258 bytes if using mbedtls_ssl_cookie_check, and possibly up to 571 bytes with a custom cookie check function.
Understanding CVE-2022-35409
This section provides insights into the nature of the CVE-2022-35409 vulnerability.
What is CVE-2022-35409?
CVE-2022-35409 is a vulnerability present in Mbed TLS versions before 2.28.1 and 3.x before 3.2.0 that allows an unauthenticated attacker to trigger a heap-based buffer over-read on a DTLS server.
The Impact of CVE-2022-35409
The impact of this vulnerability includes possible server crashes and potential information disclosure depending on the error responses generated.
Technical Details of CVE-2022-35409
In this section, we delve into the specific technical details of CVE-2022-35409.
Vulnerability Description
The vulnerability allows attackers to exploit a heap-based buffer over-read by sending a malicious ClientHello message in specific configurations.
Affected Systems and Versions
All versions of Mbed TLS before 2.28.1 and 3.x before 3.2.0 are affected by this vulnerability, under certain configuration settings.
Exploitation Mechanism
Attackers exploit the vulnerability by sending an invalid ClientHello message to a DTLS server with specific configuration settings.
Mitigation and Prevention
In this section, we discuss the steps to mitigate and prevent exploitation of CVE-2022-35409.
Immediate Steps to Take
Users should update to Mbed TLS versions 2.28.1 or 3.2.0 to address this vulnerability and disable the affected configurations.
Long-Term Security Practices
Implement strict input validation mechanisms and regularly monitor for security updates and patches.
Patching and Updates
Regularly check for security advisories from Mbed TLS and apply patches promptly to ensure system security.