CVE-2022-38178 : Security Advisory and Response

A memory leaks vulnerability in the EdDSA DNSSEC verification code could allow an attacker to trigger a small memory leak, leading to a crash due to lack of resources.

Understanding CVE-2022-38178

This section discusses the details, impact, technical aspects, and mitigation strategies related to CVE-2022-38178.

What is CVE-2022-38178?

CVE-2022-38178 pertains to a vulnerability in the BIND DNS software that can be exploited by spoofing the target resolver with responses containing a malformed EdDSA signature. This can result in a gradual depletion of available memory, potentially causing a crash.

The Impact of CVE-2022-38178

The vulnerability affects various versions of the BIND9 software, allowing an attacker to exhaust memory resources through maliciously crafted responses. This could lead to denial of service or system instability.

Technical Details of CVE-2022-38178

This section provides specific technical details regarding the vulnerability, including how it can be exploited and the systems affected.

Vulnerability Description

The vulnerability arises in the DNSSEC verification code for the EdDSA algorithm within particular versions of BIND. When encountering a signature length discrepancy, the verification process can leak memory, potentially resulting in resource exhaustion.

Affected Systems and Versions

Versions of the BIND9 software ranging from Open Source Branch 9.9 to Development Branch 9.19 are impacted by this memory leaks issue. Specific versions within these branches are susceptible to the exploitation of the vulnerability.

Exploitation Mechanism

By sending responses with malformed EdDSA signatures, an attacker can exploit this vulnerability to trigger memory leaks, gradually consuming memory until the system crashes due to resource unavailability.

Mitigation and Prevention

In this section, you will find guidance on how to mitigate the risks associated with CVE-2022-38178 and prevent potential attacks.

Immediate Steps to Take

It is recommended to disable the affected algorithms, ED25519 and ED448, in the BIND9 configuration using the 'disable-algorithms' option. This action can help prevent the exploitation of the vulnerability until a patch is applied.

Long-Term Security Practices

Ensure that regular software updates and security patches are applied to the BIND9 software to address known vulnerabilities and enhance system security.

Patching and Updates

To address CVE-2022-38178, users are advised to upgrade to the latest patched release related to their current BIND9 version. Updated versions include BIND 9.16.33, 9.18.7, 9.19.5, or specifically for BIND Supported Preview Edition, BIND 9.16.33-S1.