Vulnerability identifier: #VU32268

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-6263

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Libidn
Universal components / Libraries / Libraries used by multiple products

Vendor: GNU

Description

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

The stringprep_utf8_nfkc_normalize function in lib/nfkc.c in libidn before 1.33 allows context-dependent attackers to cause a denial of service (out-of-bounds read and crash) via crafted UTF-8 data.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Libidn: 1.0 - 1.32

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External links
http://git.savannah.gnu.org/cgit/libidn.git/commit/?id=1fbee57ef3c72db2206dd87e4162108b2f425555
http://lists.opensuse.org/opensuse-updates/2016-08/msg00005.html
http://lists.opensuse.org/opensuse-updates/2016-08/msg00098.html
http://www.debian.org/security/2016/dsa-3658
http://www.openwall.com/lists/oss-security/2016/07/20/6
http://www.openwall.com/lists/oss-security/2016/07/21/4
http://www.securityfocus.com/bid/92070
http://www.ubuntu.com/usn/USN-3068-1
http://lists.gnu.org/archive/html/help-libidn/2016-07/msg00009.html
http://security.gentoo.org/glsa/201908-06

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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.