Skip to content

[3.8] gh-97612: Fix shell injection in get-remote-certificate.py (GH-97613) #97633

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ambv merged 1 commit into from
Oct 4, 2022
+10 −18
Merged

[3.8] gh-97612: Fix shell injection in get-remote-certificate.py (GH-97613) #97633

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions Misc/NEWS.d/next/Security/2022-09-28-12-10-57.gh-issue-97612.y6NvOQ.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Fix a shell code injection vulnerability in the ``get-remote-certificate.py``
example script. The script no longer uses a shell to run ``openssl`` commands.
Issue reported and initial fix by Caleb Shortt. Patch by Victor Stinner.
25 changes: 7 additions & 18 deletions Tools/scripts/get-remote-certificate.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,8 +15,8 @@
def fetch_server_certificate (host, port):

def subproc(cmd):
from subprocess import Popen, PIPE, STDOUT
proc = Popen(cmd, stdout=PIPE, stderr=STDOUT, shell=True)
from subprocess import Popen, PIPE, STDOUT, DEVNULL
proc = Popen(cmd, stdout=PIPE, stderr=STDOUT, stdin=DEVNULL)
status = proc.wait()
output = proc.stdout.read()
return status, output
Expand All @@ -33,8 +33,8 @@ def strip_to_x509_cert(certfile_contents, outfile=None):
fp.write(m.group(1) + b"\n")
try:
tn2 = (outfile or tempfile.mktemp())
status, output = subproc(r'openssl x509 -in "%s" -out "%s"' %
(tn, tn2))
cmd = ['openssl', 'x509', '-in', tn, '-out', tn2]
status, output = subproc(cmd)
if status != 0:
raise RuntimeError('OpenSSL x509 failed with status %s and '
'output: %r' % (status, output))
Expand All @@ -45,20 +45,9 @@ def strip_to_x509_cert(certfile_contents, outfile=None):
finally:
os.unlink(tn)

if sys.platform.startswith("win"):
tfile = tempfile.mktemp()
with open(tfile, "w") as fp:
fp.write("quit\n")
try:
status, output = subproc(
'openssl s_client -connect "%s:%s" -showcerts < "%s"' %
(host, port, tfile))
finally:
os.unlink(tfile)
else:
status, output = subproc(
'openssl s_client -connect "%s:%s" -showcerts < /dev/null' %
(host, port))
cmd = ['openssl', 's_client', '-connect', '%s:%s' % (host, port), '-showcerts']
status, output = subproc(cmd)

if status != 0:
raise RuntimeError('OpenSSL connect failed with status %s and '
'output: %r' % (status, output))
Expand Down