🛡️ CVE-2021-3177 — libpython
Description
Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Python applications that accept floating-point numbers as untrusted input, as demonstrated by a 1e300 argument to c_double.from_param. This occurs because sprintf is used unsafely.
Affected software
CVE-2021-3177 is recorded against 3 packages.
- libpython
- python
- python-min
Timeline and source
Published on 11 August 2025. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
bugs.python.org (Web)
github.com (Web)
lists.apache.org (Web)
lists.debian.org (Web)
lists.debian.org (Web)
lists.debian.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
Details
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| libpython | — | — |
| python | — | — |
| python-min | — | — |
References
Similar Threats
- High BIT-libpython-2026-4519
- Low BIT-libpython-2026-3479
- Medium BIT-libpython-2026-3644
- Low BIT-libpython-2025-13462
- Medium BIT-libpython-2026-2297
More CVE 2021 advisories
Browse all of CVE 2021 in the advisory index.
Exploit Protection
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CVE-2021-3177 carries CVSS 9.5 Critical rating. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.
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