Bug 1614973 (CVE-2018-10933)

Summary:	CVE-2018-10933 libssh: Authentication Bypass due to improper message callbacks implementation
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	abhgupta, ansasaki, asn, chris.snell, cperry, dbaker, dchong, extras-orphan, jfch, jokerman, kdudka, marc.st-laurent, mpitt, negativo17, Nico.hoffmann, rdieter, redhat-bugzilla, sbalasub, security-response-team, sthangav, tcrider, trankin, xingli, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libssh 0.7.6, libssh 0.8.4	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in libssh's server-side state machine. A malicious client could create channels without first performing authentication, resulting in unauthorized access.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-25 09:48:53 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:	1637257, 1637258, 1639925, 1639926
Bug Blocks:	1614980

Description Laura Pardo 2018-08-10 21:51:40 UTC

A flaw was found in libSSH which can enable a client to bypass the authentication process and set the internal state machine maintained by the library to authenticated, enabling the (otherwise prohibited) creation of channels.

Comment 1 Doran Moppert 2018-10-09 02:21:16 UTC

Acknowledgments:

Name: the libssh team
Upstream: Peter Winter-Smith (NCC Group)

Comment 5 Doran Moppert 2018-10-16 22:56:25 UTC

Created libssh tracking bugs for this issue:

Affects: fedora-all [bug 1639925]

Comment 7 Doran Moppert 2018-10-16 22:57:22 UTC

Upstream issue:

https://bugs.libssh.org/T101

Comment 8 Doran Moppert 2018-10-16 22:57:33 UTC

External References:

https://www.libssh.org/security/advisories/CVE-2018-10933.txt

Comment 17 Doran Moppert 2018-10-18 23:24:56 UTC

Statement:

This vulnerability affects libssh shipped in Red Hat Enterprise Linux 7 Extras. No libssh packages are included in Red Hat Enterprise Linux 6 and earlier. This issue does not affect libssh2 or openssh.

This issue can only be affect applications that use libssh to implement an SSH server; SSH client functionality is not affected. No packages in Red Hat products use libssh to implement an SSH server. Therefore, no package from Red Hat that uses the libssh library is affected by this flaw.

The libssh library is available for customer or third party code to use. Such code that is linked against libssh and uses the `ssh_bind*` functions may be affected by this flaw.