Bug 1666127 (CVE-2019-6111)
Summary: | CVE-2019-6111 openssh: Improper validation of object names allows malicious server to overwrite files via scp client | ||
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Product: | [Other] Security Response | Reporter: | Sam Fowler <sfowler> |
Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
Status: | CLOSED ERRATA | QA Contact: | |
Severity: | medium | Docs Contact: | |
Priority: | medium | ||
Version: | unspecified | CC: | dawwu, jjelen, kyoshida, mvanderw, sardella |
Target Milestone: | --- | Keywords: | Security |
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | If docs needed, set a value | |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2019-11-06 00:51:47 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: | 1666128, 1666580, 1666581 | ||
Bug Blocks: | 1665788 |
Description
Sam Fowler
2019-01-15 00:36:26 UTC
Created openssh tracking bugs for this issue: Affects: fedora-all [bug 1666128] Analysis: This is a flaw in the scp client (/usr/bin/scp) shipped as a part of openssh-clients package. The flaw essentially allows a malicious scp server to possibly overwrite arbitrary files in the scp client target directory or if recursive operation (-r) is chosen than the server can manipulate subdirectories on the client machine as well, subject to the file/directory permissions. To trigger this flaw, the scp client needs to either connect to a malicious scp server or connect to a MITM scp server. Connecting to a MITM server will require the client to accept the new host key, which essentially implies that either the scp server (which the client previously connected to) has changed or there is a possible MITM attempt, both of which should be investigated by the system administrator before going ahead with the connection. Also note that, since this is a flaw in the scp utility, the SSH client is not affected. Statement: This issue affects the scp client shipped with openssh. The SSH protocol or the SSH client is not affected. For more detailed analysis please refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1666127#c2 Mitigation: This issue only affects the users of scp binary which is a part of openssh-clients package. Other usage of SSH protocol or other ssh clients is not affected. Administrators can uninstall openssh-clients for additional protection against accidental usage of this binary. Removal of openssh-clients package will make the packaged binaries like scp, ssh etc unavailable. Note: This flaw requires a malicious MITM scp server for exploitation. Use cases where trusted SCP servers are used are not affected by this flaw. This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2019:3702 https://access.redhat.com/errata/RHSA-2019:3702 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-2019-6111 |