# HG changeset patch # User Sean Farley # Date 1501542284 25200 # Node ID 55681baf4cf97c87076ea63c889f6ced868d8dc8 # Parent 08cfc4baf3ba221f5dcf3358ad049f68b9da21a3 subrepo: add tests for hg rogue ssh urls (SEC) 'ssh://' has an exploit that will pass the url blindly to the ssh command, allowing a malicious person to have a subrepo with '-oProxyCommand' which could run arbitrary code on a user's machine. In addition, at least on Windows, a pipe '|' is able to execute arbitrary commands. When this happens, let's throw a big abort into the user's face so that they can inspect what's going on. diff -r 08cfc4baf3ba -r 55681baf4cf9 tests/test-subrepo.t --- a/tests/test-subrepo.t Mon Jul 31 14:40:28 2017 -0700 +++ b/tests/test-subrepo.t Mon Jul 31 16:04:44 2017 -0700 @@ -1777,3 +1777,70 @@ +bar $ cd .. + +test for ssh exploit 2017-07-25 + + $ hg init malicious-proxycommand + $ cd malicious-proxycommand + $ echo 's = [hg]ssh://-oProxyCommand=touch${IFS}owned/path' > .hgsub + $ hg init s + $ cd s + $ echo init > init + $ hg add + adding init + $ hg commit -m init + $ cd .. + $ hg add .hgsub + $ hg ci -m 'add subrepo' + $ cd .. + $ hg clone malicious-proxycommand malicious-proxycommand-clone + updating to branch default + abort: potentially unsafe url: 'ssh://-oProxyCommand=touch${IFS}owned/path' (in subrepo s) + [255] + +also check that a percent encoded '-' (%2D) doesn't work + + $ cd malicious-proxycommand + $ echo 's = [hg]ssh://%2DoProxyCommand=touch${IFS}owned/path' > .hgsub + $ hg ci -m 'change url to percent encoded' + $ cd .. + $ rm -r malicious-proxycommand-clone + $ hg clone malicious-proxycommand malicious-proxycommand-clone + updating to branch default + abort: potentially unsafe url: 'ssh://-oProxyCommand=touch${IFS}owned/path' (in subrepo s) + [255] + +also check for a pipe + + $ cd malicious-proxycommand + $ echo 's = [hg]ssh://fakehost|shell/path' > .hgsub + $ hg ci -m 'change url to pipe' + $ cd .. + $ rm -r malicious-proxycommand-clone + $ hg clone malicious-proxycommand malicious-proxycommand-clone + updating to branch default + abort: potentially unsafe url: 'ssh://fakehost|shell/path' (in subrepo s) + [255] + +also check that a percent encoded '|' (%7C) doesn't work + + $ cd malicious-proxycommand + $ echo 's = [hg]ssh://fakehost%7Cshell/path' > .hgsub + $ hg ci -m 'change url to percent encoded pipe' + $ cd .. + $ rm -r malicious-proxycommand-clone + $ hg clone malicious-proxycommand malicious-proxycommand-clone + updating to branch default + abort: potentially unsafe url: 'ssh://fakehost|shell/path' (in subrepo s) + [255] + +and bad usernames: + $ cd malicious-proxycommand + $ echo 's = [hg]ssh://-oProxyCommand=touch owned@example.com/path' > .hgsub + $ hg ci -m 'owned username' + $ cd .. + $ rm -r malicious-proxycommand-clone + $ hg clone malicious-proxycommand malicious-proxycommand-clone + updating to branch default + abort: potentially unsafe url: 'ssh://-oProxyCommand=touch owned@example.com/path' (in subrepo s) + [255]