[CVE-2024-4030] tempfile.mkdtemp() may be readable and writeable by all users on Windows
On Windows a directory returned by tempfile.mkdtemp() would not always have permissions set to restrict reading and writing to the temporary directory by other users, instead usually inheriting the correct permissions from the default location. Alternate configurations or users without a profile directory may not have the intended permissions.
If you’re not using Windows or haven’t changed the temporary directory location then you aren’t affected by this vulnerability. On other platforms the returned directory is consistently readable and writable only by the current user.
This issue was caused by Python not supporting Unix permissions on Windows. The fix adds support for Unix “700” for the mkdir function on Windows which is used by mkdtemp() to ensure the newly created directory has the proper permissions.
The fix will be made available in CPython versions 3.13.0b1 and 3.12.4. Backports are pending for other security release streams.
Severity: Medium
Issue: https://github.com/python/cpython/issues/118486
Patch: https://github.com/python/cpython/commit/81939dad77001556c527485d31a2d0f4a75... Patch: https://github.com/python/cpython/commit/8ed546679524140d8282175411fd141fe7d...
We have updated the patch for this issue, in order to simplify the fix and properly support non-English Windows.
The patch for 3.12.4 has been applied at https://github.com/python/cpython/commit/eb29e2f5905da93333d1ce78bc98b151e76... This is the cleanest patch, as it does not involve the earlier changes.
The update to the main and 3.13 branches are at https://github.com/python/cpython/commit/8af84b503d0b62a3db0d806d39f42c1e087... and https://github.com/python/cpython/commit/9d646d084c6fec83bed7bfa72d83b2ae3cf..., respectively. This update will be released in 3.13.0b2.
Earlier versions of Python will be merged before their next source-only releases. All pull requests are linked from https://github.com/python/cpython/issues/118486
On 07/05/2024 21:57, Seth Larson wrote:
On Windows a directory returned by tempfile.mkdtemp()would not always have permissions set to restrict reading and writing to the temporary directory by other users, instead usually inheriting the correct permissions from the default location. Alternate configurations or users without a profile directory may not have the intended permissions.
If you’re not using Windows or haven’t changed the temporary directory location then you aren’t affected by this vulnerability. On other platforms the returned directory is consistently readable and writable only by the current user.
This issue was caused by Python not supporting Unix permissions on Windows. The fix adds support for Unix “700” for the mkdirfunction on Windows which is used by mkdtemp()to ensure the newly created directory has the proper permissions.
The fix will be made available in CPython versions 3.13.0b1 and 3.12.4. Backports are pending for other security release streams.
Severity: Medium
Issue: https://github.com/python/cpython/issues/118486 <https://github.com/python/cpython/issues/118486>
Patch: https://github.com/python/cpython/commit/81939dad77001556c527485d31a2d0f4a75... <https://github.com/python/cpython/commit/81939dad77001556c527485d31a2d0f4a759033e>
Patch: https://github.com/python/cpython/commit/8ed546679524140d8282175411fd141fe7d... <https://github.com/python/cpython/commit/8ed546679524140d8282175411fd141fe7df070d>
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