#VU67760 Type conversion in CPython - CVE-2020-10735

Vulnerability identifier: #VU67760

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-10735

CWE-ID: CWE-704

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
CPython
Universal components / Libraries / Scripting languages

Vendor: Python.org

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a type confusion in algorithms with quadratic time complexity when using non-binary bases within the int() call. A remote attacker can pass specially crafted data to the affected application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

CPython: 3.7.0 - 3.7.13, 3.8.0 - 3.8.13, 3.9.0 - 3.9.13, 3.10.0 - 3.10.6

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External links
https://access.redhat.com/security/cve/CVE-2020-10735
https://docs.google.com/document/d/1KjuF_aXlzPUxTK4BMgezGJ2Pn7uevfX7g0_mvgHlL7Y
https://bugzilla.redhat.com/show_bug.cgi?id=1834423
https://github.com/python/cpython/issues/95778
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EWKR2SPX3JORLWCXFY3KN2U5B5CIUQQ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2VCU6EVQDIXNCEDJUCTFIER2WVNNDTYZ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/V7ZUJDHK7KNG6SLIFXW7MNZ6O2PUJYK6/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/HSRPVJZL6DJFWKYRHMNJB7VCEUCBKRF5/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6XL6E5A3I36TRR73VNBOXNIQP4AMZDFZ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U4ZZV4CDFRMTPDBI7C5L43RFL3XLIGUY/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/32AAQKABEKFCB5DDV5OONRZK6BS23HPW/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SZYJSGLSCQOKXXFVJVJQAXLEOJBIWGEL/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OT5WQB7Z3CXOWVBD2AFAHYPA5ONYFFZ4/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UBPDVCDIUCEBE7C4NAGNA2KQJYOTPBAZ/
https://www.openwall.com/lists/oss-security/2022/09/21/1
https://www.openwall.com/lists/oss-security/2022/09/21/4
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OKYE2DOI2X7WZXAWTQJZAXYIWM37HDCY/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PD7FTLJOIGMUSCDR3JAN6WRFHJEE4PH5/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OT5U223OE5ZOUHZAZYSYSWVJQIKDE73E/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/76YE7AM37MRU76XJV4M27CWDAMUGNRYK/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZEOAJWGGY55QU35UM2OVZATBW5MX2OZD/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.