Bug 1713433 (CVE-2019-10150)
| Summary: | CVE-2019-10150 atomic-openshift: OpenShift builds don't verify SSH Host Keys for the git repository | ||
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| Product: | [Other] Security Response | Reporter: | Pedro Sampaio <psampaio> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED ERRATA | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | adam.kaplan, admiller, ahardin, aos-bugs, bleanhar, bmontgom, ccoleman, dbaker, dedgar, dominik.mierzejewski, eparis, jburrell, jcajka, jgoulding, jokerman, mchappel, nstielau, security-response-team, sponnaga, wzheng |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: |
It was found that OpenShift Container Platform does not perform SSH Host Key checking when using ssh key authentication during builds. An attacker, with the ability to redirect network traffic, could use this to alter the resulting build output.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2019-10-14 12:51:19 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 1713446, 1713671, 1713673, 1713674, 1713675, 1713676, 1715256, 1745789, 1755138 | ||
| Bug Blocks: | 1711901 | ||
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Description
Pedro Sampaio
2019-05-23 16:13:36 UTC
Created repro; confirmed against 3.9, 3.11 and 4.1 rc5. Tracked to scmauth/sshkey.go within builder. Link here is for 3.11 https://github.com/openshift/origin/blob/release-3.11/pkg/build/builder/cmd/scmauth/sshkey.go#L26-L28 content := "#!/bin/sh\nssh -i " + filepath.Join(baseDir, SSHPrivateKeyMethodName) + " -o StrictHostKeyChecking=false \"$@\"\n" Flagging 3.6 and later as all affected from observation of source code. Acknowledgments: Name: @l14n_uk Statement: OpenShift Container Platform allows for various types of "source clone secrets" to be defined in order to permit building from non-public git repositories. When using ssh key authentication, the server host key checking function is disabled. An attacker with the ability to redirect the network traffic and perform a "man in the middle" attack will be able to redirect the build job to use arbitrary content of their choosing. Note that the same flaw (non-verification of remote server) is present when using HTTP, or when using HTTPS with TLS verification manually disabled. External References: https://docs.openshift.com/container-platform/3.11/dev_guide/builds/build_inputs.html#source-secrets-ssh-key-authentication Mitigation: Use only methods (such as HTTPS with TLS verification) that enable the identity of the remote repository to be validated. Updating CVSS to align to other MITM style flaws. - MITM can be performed through many means (DNS redirection, traffic redirection, etc), leading to a complex attack. - Attacking user needs no local privs on the cluster, and with MITM abilities can observe traffic requests in order to construct their attack. - Scope is unchanged - whatever permissions in the cluster the builder pod has, they remain the same with the altered build content. Created origin tracking bugs for this issue: Affects: fedora-all [bug 1715256] This issue has been addressed in the following products: Red Hat OpenShift Container Platform 3.10 Via RHSA-2019:2989 https://access.redhat.com/errata/RHSA-2019:2989 This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2019-10150 This issue has been addressed in the following products: Red Hat OpenShift Container Platform 4.1 Via RHSA-2019:3007 https://access.redhat.com/errata/RHSA-2019:3007 This issue has been addressed in the following products: Red Hat OpenShift Container Platform 3.11 Via RHSA-2019:3143 https://access.redhat.com/errata/RHSA-2019:3143 This issue has been addressed in the following products: Red Hat OpenShift Container Platform 3.9 Via RHSA-2019:3811 https://access.redhat.com/errata/RHSA-2019:3811 |