Bug 1348470
| Summary: | Arbitrary code execution due to insecure loading of Python module(s) from CWD | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Dhiru Kholia <dkholia> |
| Component: | python2 | Assignee: | Charalampos Stratakis <cstratak> |
| Status: | CLOSED WONTFIX | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | 29 | CC: | bkabrda, cstratak, dmalcolm, ivazqueznet, jonathansteffan, mhroncok, pviktori, rkuska, tomspur, torsava, vstinner |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2018-11-26 13:04:22 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 1348410 | ||
This message is a reminder that Fedora 24 is nearing its end of life. Approximately 2 (two) weeks from now Fedora will stop maintaining and issuing updates for Fedora 24. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '24'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 24 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. Also reproduced on Fedora 26. Changing the script to the following fixes the issue:
#!/bin/bash
exec `python -s -c "import sys; del sys.path[0]; from distutils.sysconfig import get_python_lib; print(get_python_lib(plat_specific = True))"`/pynche/pynche
Also note that is still works even if sys.py (with print('boom!')) is in CWD.
FWIW, that mess is added in Fedora, to work around multilib trouble (see bug #831437) I propose to chane it to the following instead: #!/usr/bin/python from pynche import Main Main.main() (This is technically private API, but I don't see it changing in Python2's lifetime.) er, #!/usr/bin/python2 of course This message is a reminder that Fedora 25 is nearing its end of life. Approximately 4 (four) weeks from now Fedora will stop maintaining and issuing updates for Fedora 25. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '25'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 25 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. This message is a reminder that Fedora 26 is nearing its end of life. Approximately 4 (four) weeks from now Fedora will stop maintaining and issuing updates for Fedora 26. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '26'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 26 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. This is a low priority for us and we'll probably never get to it, unless somebody says it's a higher priority for them. This bug appears to have been reported against 'rawhide' during the Fedora 29 development cycle. Changing version to '29'. Sadly, the described behavior is a deliberate choice to make Python "practical" to use. This issue has been fixed in Python 3.4 by adding a new -I (isolated mode) which prevents to add the path of script or the current directory to sys.path. Example: $ python3 -c 'import pprint, sys; pprint.pprint(sys.path)' ['', '/usr/lib64/python36.zip', '/usr/lib64/python3.6', '/usr/lib64/python3.6/lib-dynload', ...] $ python3 -I -c 'import pprint, sys; pprint.pprint(sys.path)' ['/usr/lib64/python36.zip', '/usr/lib64/python3.6', '/usr/lib64/python3.6/lib-dynload', ...] The default behavior has not been changed, it's an opt-in option. |
The /usr/bin/pynche script from the python-tools package tries to load the "distutils" Python module from the current working directory (CWD). Steps to Reproduce: $ cat > distutils.py print("boom!") $ pynche # run /usr/bin/pynche ...boom!... Additional info: This bug is very similar to https://bugzilla.redhat.com/show_bug.cgi?id=995060