#VU33794 Input validation error in Fedora - CVE-2016-8605

Vulnerability identifier: #VU33794

Vulnerability risk: Medium

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

CVE-ID: CVE-2016-8605

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Fedora
Operating systems & Components / Operating system

Vendor: Fedoraproject

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

The mkdir procedure of GNU Guile temporarily changed the process' umask to zero. During that time window, in a multithreaded application, other threads could end up creating files with insecure permissions. For example, mkdir without the optional mode argument would create directories as 0777. This is fixed in Guile 2.0.13. Prior versions are affected.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Fedora: 23 - 25

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External links
https://www.openwall.com/lists/oss-security/2016/10/12/1
https://www.securityfocus.com/bid/93510
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6QTAGSDCTYXTABAA77BQJGNKOOBRV4DK/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FNVE5N24FLWDYBQ3LAFMF6BFCWKDO7VM/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UJP5S36GTXMDEBXWF6LKKV76DSLNQG44/

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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.