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RUSTSEC-2025-0020

Risk of buffer overflow in PyString::from_object
Reported
Issued
Package
pyo3 (crates.io)
Type
Vulnerability
Categories
Keywords
#buffer-overflow
References
Patched
  • >=0.24.1
Affected Functions
Version
pyo3::types::PyString::from_object
  • <0.24.1
pyo3::types::PyString::from_object_bound
  • <0.24.1
  • >=0.21.0

Description

PyString::from_object took &str arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the &str data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow).

In PyO3 0.24.1 this function will now allocate a CString to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes &CStr arguments.

Advisory available under CC0-1.0 license.