CVE-2019-3689

The nfs-utils package in SUSE Linux Enterprise Server 12 before and including version 1.3.0-34.18.1 and in SUSE Linux Enterprise Server 15 before and including version 2.1.1-6.10.2 the directory /var/lib/nfs is owned by statd:nogroup. This directory contains files owned and managed by root. If statd is compromised, it can therefore trick processes running with root privileges into creating/overwriting files anywhere on the system.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Affected Software

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00071.html
• http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00006.html
• https://bugzilla.suse.com/show_bug.cgi?id=1150733
• https://git.linux-nfs.org/?p=steved/nfs-utils.git%3Ba=commitdiff%3Bh=fee2cc29e888f2ced6a76990923aef19d326dc0e
• https://lists.debian.org/debian-lts-announce/2019/10/msg00026.html
• https://usn.ubuntu.com/4400-1/