CVE-2023-7008 is a vulnerability identified in the systemd-resolved component of Red Hat Enterprise Linux 8. Systemd-resolved is responsible for DNS resolution and DNSSEC validation, which ensures the authenticity and integrity of DNS responses by verifying cryptographic signatures. The vulnerability allows systemd-resolved to accept DNSSEC-signed domain records even when these records lack valid signatures. This flaw effectively bypasses the DNSSEC validation mechanism, permitting man-in-the-middle attackers or malicious upstream DNS resolvers to inject or manipulate DNS records without detection. Such manipulation can redirect users to malicious sites, facilitate phishing, or intercept sensitive communications. The vulnerability is exploitable remotely over the network without requiring authentication or user interaction, but the attack complexity is rated high, likely due to the need to control or influence DNS traffic paths. The CVSS v3.1 score is 5.9 (medium severity), with an attack vector of network, no privileges required, no user interaction, and impact limited to integrity compromise without affecting confidentiality or availability. No known exploits have been reported in the wild as of the publication date. The vulnerability was published on December 23, 2023, and is currently in the published state with no patch links provided yet. Organizations using RHEL 8 with systemd-resolved enabled and relying on DNSSEC for secure DNS resolution are vulnerable to this issue.

For European organizations, this vulnerability poses a significant risk to the integrity of DNS resolution processes, especially for entities relying on DNSSEC to secure domain name lookups. Manipulated DNS responses can lead to traffic redirection, enabling phishing attacks, credential theft, or interception of sensitive data. Critical infrastructure providers, financial institutions, and government agencies that depend on RHEL 8 for their servers or network appliances could experience targeted attacks exploiting this flaw. The impact is primarily on data integrity rather than confidentiality or availability, but the consequences of DNS manipulation can cascade into broader security incidents. Since no authentication or user interaction is required, attackers with network access or control over upstream DNS resolvers can exploit this vulnerability. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure. European organizations with stringent compliance requirements around data integrity and secure communications must prioritize addressing this vulnerability to maintain trust and operational security.

Organizations should monitor Red Hat’s advisories closely and apply patches or updates to systemd-resolved as soon as they become available. In the interim, administrators can enforce stricter DNSSEC validation policies by configuring systemd-resolved or alternative DNS resolvers to reject unsigned or improperly signed DNSSEC records explicitly. Deploying network-level DNS filtering or DNSSEC-validating recursive resolvers can add an additional layer of protection. Network segmentation and limiting exposure of critical DNS infrastructure to untrusted networks can reduce the attack surface. Monitoring DNS traffic for anomalies, such as unexpected DNS record changes or signature validation failures, can help detect exploitation attempts early. Additionally, organizations should review their DNS resolver configurations to ensure they do not rely on potentially compromised upstream resolvers and consider using trusted DNS providers with strong DNSSEC enforcement. Incident response plans should include procedures for DNS-related incidents to quickly mitigate any exploitation consequences.