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| author |  Joey Hess <joeyh@joeyh.name> | 2017-08-17 22:11:31 -0400 |
|---|---|---|
| committer | Joey Hess <joeyh@joeyh.name> | 2017-08-17 22:11:31 -0400 |
| commit | c1aec2ae837c24b602c7a0ca3fc7b0fcad565758 (patch) | |
| tree | 6ce58560d65d4a3a6529569cfdde4c80b6b5e5bf /Remote/GCrypt.hs | |
| parent | d998fce1481a4bc7779e21cb2ff6a0fa42d72c7a (diff) | |
avoid the dashed ssh hostname class of security holes
Security fix: Disallow hostname starting with a dash, which would get
passed to ssh and be treated an option. This could be used by an attacker
who provides a crafted ssh url (for eg a git remote) to execute arbitrary
code via ssh -oProxyCommand.
No CVE has yet been assigned for this hole.
The same class of security hole recently affected git itself,
CVE-2017-1000117.
Method: Identified all places where ssh is run, by git grep '"ssh"'
Converted them all to use a SshHost, if they did not already, for
specifying the hostname.
SshHost was made a data type with a smart constructor, which rejects
hostnames starting with '-'.
Note that git-annex already contains extensive use of Utility.SafeCommand,
which fixes a similar class of problem where a filename starting with a
dash gets passed to a program which treats it as an option.
This commit was sponsored by Jochen Bartl on Patreon.
Diffstat (limited to 'Remote/GCrypt.hs')
| -rw-r--r-- | Remote/GCrypt.hs | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Remote/GCrypt.hs b/Remote/GCrypt.hs index ee949ea08..2ccc47ad8 100644 --- a/Remote/GCrypt.hs +++ b/Remote/GCrypt.hs @@ -48,6 +48,7 @@ import Utility.Rsync import Utility.Tmp import Logs.Remote import Utility.Gpg +import Utility.SshHost remote :: RemoteType remote = RemoteType { @@ -158,8 +159,9 @@ rsyncTransport r gc let rsyncpath = if "/~/" `isPrefixOf` path then drop 3 path else path - opts <- sshOptions ConsumeStdin (host, Nothing) gc [] - return (rsyncShell $ Param "ssh" : opts, host ++ ":" ++ rsyncpath, AccessShell) + let sshhost = either error id (mkSshHost host) + opts <- sshOptions ConsumeStdin (sshhost, Nothing) gc [] + return (rsyncShell $ Param "ssh" : opts, fromSshHost sshhost ++ ":" ++ rsyncpath, AccessShell) othertransport = return ([], loc, AccessDirect) noCrypto :: Annex a |