#VU41102 Race condition in Python - CVE-2014-2667

Vulnerability identifier: #VU41102

Vulnerability risk: Medium

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2014-2667

CWE-ID: CWE-362

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 read and manipulate data.

Race condition in the _get_masked_mode function in Lib/os.py in Python 3.2 through 3.5, when exist_ok is set to true and multiple threads are used, might allow local users to bypass intended file permissions by leveraging a separate application vulnerability before the umask has been set to the expected value.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Python: 3.2.0 - 3.2.6, 3.3.0 - 3.3.6, 3.4.0 - 3.4.2

---

External links
https://bugs.python.org/issue21082
https://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
https://lists.opensuse.org/opensuse-updates/2014-05/msg00007.html
https://lists.opensuse.org/opensuse-updates/2014-05/msg00008.html
https://www.openwall.com/lists/oss-security/2014/03/28/15
https://www.openwall.com/lists/oss-security/2014/03/29/5
https://www.openwall.com/lists/oss-security/2014/03/30/4
https://security.gentoo.org/glsa/201503-10

---

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.