RHSA-2017:0127 - Security Advisory

Topic

An update for runc is now available for Red Hat Enterprise Linux 7 Extras.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The runC tool is a lightweight, portable implementation of the Open Container Format (OCF) that provides container runtime.

Security Fix(es):

• The runc component used by `docker exec` feature of docker allowed additional container processes via to be ptraced by the pid 1 of the container. This allows the main processes of the container, if running as root, to gain low-level access to these new processes during initialization. An attacker can, depending on the nature of the incoming process, leverage this to elevate access to the host. This ranges from accessing host content through the file descriptors of the incoming process to, potentially, a complete container escape by leveraging memory access or syscall interception. (CVE-2016-9962)

Red Hat would like to thank the Docker project for reporting this issue. Upstream acknowledges Aleksa Sarai (SUSE) and Tonis Tiigi (Docker) as the original reporters.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64

Fixes

• BZ - 1409531 - CVE-2016-9962 docker: insecure opening of file-descriptor allows privilege escalation

CVEs

• CVE-2016-9962

References

• https://access.redhat.com/security/updates/classification/#moderate