systemd CVE-2018-21029 Certificate Validation Security Bypass Vulnerability

Description

systemd is prone to a security-bypass vulnerability. An attacker can exploit this issue to perform man-in-the-middle attacks and perform certain unauthorized actions, which will aid in further attacks. systemd versions 239 through 243 are vulnerable.

Technologies Affected

• systemd systemd 239
• systemd systemd 240
• systemd systemd 242
• systemd systemd 243

Recommendations

Block external access at the network boundary, unless external parties require service.
If global access isn’t needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.

Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review its logs regularly.

Updates are available. Please see the references or vendor advisory for more information.