#VU41776 Input validation error in Python - CVE-2013-7338

Vulnerability identifier: #VU41776

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2013-7338

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Python
Universal components / Libraries / Scripting languages

Vendor: Python.org

Description

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

Python before 3.3.4 RC1 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a file size value larger than the size of the zip file to the (1) ZipExtFile.read, (2) ZipExtFile.read(n), (3) ZipExtFile.readlines, (4) ZipFile.extract, or (5) ZipFile.extractall function.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Python: 3.3.0 - 3.3.3

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External links
https://bugs.python.org/issue20078
https://hg.python.org/cpython/rev/79ea4ce431b1
https://lists.apple.com/archives/security-announce/2015/Aug/msg00001.html
https://lists.opensuse.org/opensuse-updates/2014-05/msg00008.html
https://seclists.org/oss-sec/2014/q1/592
https://seclists.org/oss-sec/2014/q1/595
https://www.securityfocus.com/bid/65179
https://www.securitytracker.com/id/1029973
https://docs.python.org/3.3/whatsnew/changelog.html
https://security.gentoo.org/glsa/201503-10
https://support.apple.com/kb/HT205031

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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.