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author | Joey Hess <joeyh@joeyh.name> | 2017-08-17 22:11:31 -0400 |
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committer | Joey Hess <joeyh@joeyh.name> | 2017-08-17 22:11:31 -0400 |
commit | c1aec2ae837c24b602c7a0ca3fc7b0fcad565758 (patch) | |
tree | 6ce58560d65d4a3a6529569cfdde4c80b6b5e5bf /Remote/Rsync.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/Rsync.hs')
-rw-r--r-- | Remote/Rsync.hs | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/Remote/Rsync.hs b/Remote/Rsync.hs index 681052e68..4fc55d725 100644 --- a/Remote/Rsync.hs +++ b/Remote/Rsync.hs @@ -38,6 +38,7 @@ import Types.Transfer import Types.Creds import Annex.DirHashes import Utility.Tmp +import Utility.SshHost import qualified Data.Map as M @@ -120,7 +121,8 @@ rsyncTransport gc url case fromNull ["ssh"] (remoteAnnexRsyncTransport gc) of "ssh":sshopts -> do let (port, sshopts') = sshReadPort sshopts - userhost = takeWhile (/=':') url + userhost = either error id $ mkSshHost $ + takeWhile (/= ':') url (Param "ssh":) <$> sshOptions ConsumeStdin (userhost, port) gc (map Param $ loginopt ++ sshopts') |