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Author SHA1 Message Date
Michal Domonkos
a164f6afbf Bump release 2018-08-31 18:55:03 +02:00
Michal Domonkos
cbf5de66f6 reposync: prevent path traversal (CVE-2018-10897)
Resolves: bug#1600454
2018-08-31 18:53:45 +02:00
2 changed files with 126 additions and 1 deletions

View file

@ -0,0 +1,119 @@
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 2018-08-31 15:14:08.100322216 +0200
+++ yum-utils-1.1.31/docs/reposync.1 2018-08-31 15:14:14.680403500 +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 2018-08-31 15:14:08.112322364 +0200
+++ yum-utils-1.1.31/reposync.py 2018-08-31 15:14:14.680403500 +0200
@@ -75,6 +75,12 @@ 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
@@ -117,6 +123,10 @@ 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)
@@ -217,13 +227,36 @@ 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:
@@ -270,8 +303,7 @@ def main():
remote_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
@@ -283,10 +315,9 @@ def main():
download_list.sort(key=lambda pkg: pkg.name)
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
@@ -295,8 +326,7 @@ 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)

View file

@ -10,12 +10,13 @@
Summary: Utilities based around the yum package manager
Name: yum-utils
Version: 1.1.31
Release: 514%{?dist}
Release: 515%{?dist}
License: GPLv2+
Group: Development/Tools
Source: http://yum.baseurl.org/download/yum-utils/%{name}-%{version}.tar.gz
Patch1: yum-utils-HEAD.patch
Patch2: yum-utils-deprecated.patch
Patch3: reposync-prevent-path-traversal.patch
URL: http://yum.baseurl.org/download/yum-utils/
BuildArch: noarch
Requires: yum >= 3.4.3-148
@ -374,6 +375,7 @@ This plugin touches rpmdb files to work around overlayfs issues.
%setup -q
%patch1 -p1
%patch2 -p1
%patch3 -p1
%install
rm -rf $RPM_BUILD_ROOT
@ -673,6 +675,10 @@ touch $RPM_BUILD_ROOT%{_sysconfdir}/yum.repos.d/_local.repo
%{pluginhome}/ovl.*
%changelog
* Fri Aug 31 2018 Michal Domonkos <mdomonko@redhat.com> - 1.1.31-515
- reposync: prevent path traversal (CVE-2018-10897)
- Resolves: bug#1600454
* Fri Feb 09 2018 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.31-514
- Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild