CVE-2020-27833: Input Validation
A vulnerability was found in all versions of the oc binary packaged in openshift-clients, limited to the oc image extract command. An arbitrary file read and/or write can be achieved using a specially crafted container image (.tar file) that holds symbolic links. When a symbolic link is first created pointing within the tarball this bypasses the existing path checks. Subsequent symbolic links can then be created to link outside of the tarball's parent directory. If an executable or configuration file can be overwritten as a result, the vulnerability can turn into arbitrary code execution.
Other sources
A Zip Slip vulnerability was found in the oc binary in openshift-clients where an arbitrary file write is achieved by using a specially crafted raw container image (.tar file) which contains symbolic links. The vulnerability is limited to the command oc image extract. If a symbolic link is first created pointing within the tarball, this allows further symbolic links to bypass the existing path check. This flaw allows the tarball to create links outside the tarball's parent directory, allowing for executables or configuration files to be overwritten, resulting in arbitrary code execution. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. Versions up to and including openshift-clients-4.7.0-202104250659.p0.git.95881af are affected.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2020-27833?
CVE-2020-27833 has a medium severity level due to the potential for arbitrary file read and write operations.
How can I fix CVE-2020-27833?
To fix CVE-2020-27833, upgrade to a version of openshift-clients that is later than a fixed release for versions 4.7 of Red Hat OpenShift Container Platform.
Which versions of OpenShift Container Platform are affected by CVE-2020-27833?
CVE-2020-27833 affects all versions of OpenShift Container Platform up to 4.7.
What components are impacted by CVE-2020-27833?
CVE-2020-27833 specifically impacts the 'oc' binary and the 'oc image extract' command in the OpenShift clients.
What kind of exploit can CVE-2020-27833 enable?
CVE-2020-27833 enables malicious actors to read from or write to arbitrary files through crafted container images with symbolic links.