CVE-2018-1118

Linux kernel vhost since version 4.8 does not properly initialize memory in messages passed between virtual guests and the host operating system in the vhost/vhost.c:vhost_new_msg() function. This can allow local privileged users to read some kernel memory contents when reading from the /dev/vhost-net device file.

Weakness

The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable’s type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• https://access.redhat.com/errata/RHSA-2018:2948
• https://access.redhat.com/errata/RHSA-2018:3083
• https://access.redhat.com/errata/RHSA-2018:3096
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1118
• https://lists.debian.org/debian-lts-announce/2018/07/msg00020.html
• https://usn.ubuntu.com/3762-1/
• https://usn.ubuntu.com/3762-2/