diff -up yum-utils-1.1.31/docs/reposync.1.orig yum-utils-1.1.31/docs/reposync.1

--- yum-utils-1.1.31/docs/reposync.1.orig	2018-07-20 11:01:16.789747160 +0200

+++ yum-utils-1.1.31/docs/reposync.1	2018-07-20 11:01:21.765700655 +0200

@@ -47,6 +47,16 @@ Download all the non-default metadata.

 Download only newest packages per-repo.

 .IP "\fB\-q, \-\-quiet\fP"

 Output as little information as possible.

+.IP "\fB\-\-allow-path-traversal\fP"

+Allow packages stored outside their repo directory to be synced.

+These are packages that are referenced in metadata by using absolute paths or

+up-level ".." symbols, and are normally skipped by \fBreposync\fR for security

+reasons.

+

+\fBCAUTION:\fR Using this option has potential security implications since, by

+providing malicious repodata, an attacker could make \fBreposync\fR write to

+arbitrary locations on the file system that are accessible by the user running

+it.

 .SH "EXAMPLES"

 .IP "Sync all packages from the 'updates' repo to the current directory:"

 \fB reposync \-\-repoid=updates\fP

diff -up yum-utils-1.1.31/reposync.py.orig yum-utils-1.1.31/reposync.py

--- yum-utils-1.1.31/reposync.py.orig	2018-07-20 11:01:16.752747506 +0200

+++ yum-utils-1.1.31/reposync.py	2018-07-20 11:01:54.717392693 +0200

@@ -84,6 +84,12 @@ def localpkgs(directory):

             cache[name] = { 'path': fn, 'size': st.st_size, 'device': st.st_dev }

     return cache

+def is_subpath(path, root):

+    root = os.path.realpath(root)

+    path = os.path.realpath(os.path.join(root, path))

+    # join() is used below to ensure root ends with a slash

+    return path.startswith(os.path.join(root, ''))

+

 def parseArgs():

     usage = """

     Reposync is used to synchronize a remote yum repository to a local 

@@ -126,6 +132,10 @@ def parseArgs():

     parser.add_option("","--download-metadata", dest="downloadmd", 

         default=False, action="store_true", 

         help="download all the non-default metadata")

+    parser.add_option("", "--allow-path-traversal", default=False,

+        action="store_true",

+        help="Allow packages stored outside their repo directory to be synced "

+             "(UNSAFE, USE WITH CAUTION!)")

     (opts, args) = parser.parse_args()

     return (opts, args)

@@ -226,13 +236,36 @@ def main():

         else:

             local_repo_path = opts.destdir + '/' + repo.id

+        # Ensure we don't traverse out of local_repo_path by dropping any

+        # packages whose remote_path is absolute or contains up-level

+        # references (unless explicitly allowed).

+        # See RHBZ#1600221 for details.

+        if not opts.allow_path_traversal:

+            newlist = []

+            skipped = False

+            for pkg in download_list:

+                if is_subpath(pkg.remote_path, local_repo_path):

+                    newlist.append(pkg)

+                    continue

+                my.logger.warning(

+                    'WARNING: skipping package %s: remote path "%s" not '

+                    'within repodir, unsafe to mirror locally'

+                    % (pkg, pkg.remote_path)

+                )

+                skipped = True

+            if skipped:

+                my.logger.info(

+                    'You can enable unsafe remote paths by using '

+                    '--allow-path-traversal (see reposync(1) for details)'

+                )

+            download_list = newlist

+

         if opts.delete and os.path.exists(local_repo_path):

             current_pkgs = localpkgs(local_repo_path)

             download_set = {}

             for pkg in download_list:

-                remote = pkg.returnSimple('relativepath')

-                rpmname = os.path.basename(remote)

+                rpmname = os.path.basename(pkg.remote_path)

                 download_set[rpmname] = 1

             for pkg in current_pkgs:

@@ -280,8 +313,7 @@ def main():

         local_size  = 0

         if not opts.urls:

             for pkg in download_list:

-                remote = pkg.returnSimple('relativepath')

-                local = local_repo_path + '/' + remote

+                local = os.path.join(local_repo_path, pkg.remote_path)

                 sz = int(pkg.returnSimple('packagesize'))

                 if os.path.exists(local) and os.path.getsize(local) == sz:

                     continue

@@ -293,10 +325,9 @@ def main():

         download_list.sort(sortPkgObj)

         if opts.urls:

             for pkg in download_list:

-                remote = pkg.returnSimple('relativepath')

-                local = os.path.join(local_repo_path, remote)

+                local = os.path.join(local_repo_path, pkg.remote_path)

                 if not (os.path.exists(local) and my.verifyPkg(local, pkg, False)):

-                    print urljoin(pkg.repo.urls[0], pkg.relativepath)

+                    print urljoin(pkg.repo.urls[0], pkg.remote_path)

             continue

         # create dest dir

@@ -305,8 +336,7 @@ def main():

         # set localpaths

         for pkg in download_list:

-            rpmfn = pkg.remote_path

-            pkg.localpath = os.path.join(local_repo_path, rpmfn)

+            pkg.localpath = os.path.join(local_repo_path, pkg.remote_path)

             pkg.repo.copy_local = True

             pkg.repo.cache = 0

             localdir = os.path.dirname(pkg.localpath)