diff options
| -rw-r--r-- | Misc/NEWS.d/next/Security/2022-09-28-12-10-57.gh-issue-97612.y6NvOQ.rst | 3 | ||||
| -rwxr-xr-x | Tools/scripts/get-remote-certificate.py | 25 |
2 files changed, 10 insertions, 18 deletions
diff --git a/Misc/NEWS.d/next/Security/2022-09-28-12-10-57.gh-issue-97612.y6NvOQ.rst b/Misc/NEWS.d/next/Security/2022-09-28-12-10-57.gh-issue-97612.y6NvOQ.rst new file mode 100644 index 0000000..2f11349 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2022-09-28-12-10-57.gh-issue-97612.y6NvOQ.rst @@ -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. diff --git a/Tools/scripts/get-remote-certificate.py b/Tools/scripts/get-remote-certificate.py index 3890128..68272fc 100755 --- a/Tools/scripts/get-remote-certificate.py +++ b/Tools/scripts/get-remote-certificate.py @@ -15,8 +15,8 @@ import tempfile 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 @@ -33,8 +33,8 @@ def fetch_server_certificate (host, port): 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)) @@ -45,20 +45,9 @@ def fetch_server_certificate (host, port): 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)) |