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    Dashboard / CVE / CVE-2021-3177

    CVE-2021-3177

    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.

    Published:Jan 19, 2021
    Last Modified:Dec 18, 2025
    EPS:Jan 19, 2021
    EPSS Score:0.00072
    CVSS Score:9.8

    Affected Products

    Vendor
    Debian
    Product
    Debian Linux
    Vendor
    Fedoraproject
    Product
    Fedora
    Vendor
    Netapp
    Product
    Active Iq Unified Manager
    Vendor
    Netapp
    Product
    Ontap Select Deploy Administration Utility
    Vendor
    Oracle
    Product
    Communications Cloud Native Core Network Function Cloud Native Environment
    Vendor
    Oracle
    Product
    Communications Offline Mediation Controller
    Vendor
    Oracle
    Product
    Communications Pricing Design Center
    Vendor
    Oracle
    Product
    Enterprise Manager Ops Center
    Vendor
    Oracle
    Product
    Zfs Storage Appliance Kit
    Vendor
    Python
    Product
    Python
    Vendor
    Redhat
    Product
    Enterprise Linux
    Vendor
    Redhat
    Product
    Rhel Software Collections

    Exploits

    https://bugs.python.org/issue42938https://bugs.python.org/issue42938

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    References

    https://bugs.python.org/issue42938
    https://github.com/python/cpython/pull/24239
    https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
    https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html
    https://lists.debian.org/debian-lts-announce/2022/02/msg00013.html
    https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRHOCQYX3QLDGDQGTWQAUUT2GGIZCZUO/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CCFZMVRQUKCBQIG5F2CBVADK63NFSE4A/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FONHJIOZOFD7CD35KZL6SVBUTMBPGZGA/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FPE7SMXYUIWPOIZV4DQYXODRXMFX3C5E/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HCQTCSP6SCVIYNIRUJC5X7YBVUHPLSC4/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MGSV6BJQLRQ6RKVUXK7JGU7TP4QFGQXC/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MP572OLHMS7MZO4KUPSCIMSZIA5IZZ62/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NODWHDIFBQE5RU5PUWUVE47JOT5VCMJ2/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NQPARTLNSFQVMMQHPNBFOCOZOO3TMQNA/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NXSMBHES3ANXXS2RSO5G6Q24BR4B2PWK/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V6XJAULOS5JVB2L67NCKKMJ5NTKZJBSD/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y4KSYYWMGAKOA2JVCQA422OINT6CKQ7O/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YDTZVGSXQ7HR7OCGSUHTRNTMBG43OMKU/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7GZV74KM72O2PEJN2C4XP3V5Q5MZUOO/
    https://news.ycombinator.com/item?id=26185005
    https://python-security.readthedocs.io/vuln/ctypes-buffer-overflow-pycarg_repr.html
    https://security.gentoo.org/glsa/202101-18
    https://security.netapp.com/advisory/ntap-20210226-0003/
    https://www.oracle.com//security-alerts/cpujul2021.html
    https://www.oracle.com/security-alerts/cpujan2022.html
    https://www.oracle.com/security-alerts/cpujul2022.html
    https://www.oracle.com/security-alerts/cpuoct2021.html
    https://bugs.python.org/issue42938
    https://github.com/python/cpython/pull/24239
    https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
    https://lists.debian.org/debian-lts-announce/2021/04/msg00005.html
    https://lists.debian.org/debian-lts-announce/2022/02/msg00013.html
    https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRHOCQYX3QLDGDQGTWQAUUT2GGIZCZUO/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CCFZMVRQUKCBQIG5F2CBVADK63NFSE4A/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FONHJIOZOFD7CD35KZL6SVBUTMBPGZGA/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FPE7SMXYUIWPOIZV4DQYXODRXMFX3C5E/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HCQTCSP6SCVIYNIRUJC5X7YBVUHPLSC4/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MGSV6BJQLRQ6RKVUXK7JGU7TP4QFGQXC/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MP572OLHMS7MZO4KUPSCIMSZIA5IZZ62/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NODWHDIFBQE5RU5PUWUVE47JOT5VCMJ2/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NQPARTLNSFQVMMQHPNBFOCOZOO3TMQNA/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NXSMBHES3ANXXS2RSO5G6Q24BR4B2PWK/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V6XJAULOS5JVB2L67NCKKMJ5NTKZJBSD/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y4KSYYWMGAKOA2JVCQA422OINT6CKQ7O/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YDTZVGSXQ7HR7OCGSUHTRNTMBG43OMKU/
    https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7GZV74KM72O2PEJN2C4XP3V5Q5MZUOO/
    https://news.ycombinator.com/item?id=26185005
    https://python-security.readthedocs.io/vuln/ctypes-buffer-overflow-pycarg_repr.html
    https://security.gentoo.org/glsa/202101-18
    https://security.netapp.com/advisory/ntap-20210226-0003/
    https://www.oracle.com//security-alerts/cpujul2021.html
    https://www.oracle.com/security-alerts/cpujan2022.html
    https://www.oracle.com/security-alerts/cpujul2022.html
    https://www.oracle.com/security-alerts/cpuoct2021.html

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High