CVE-2016-6263

Publication date 21 July 2016

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libidn	17.04 zesty	Not affected
	16.10 yakkety	Not affected
	16.04 LTS xenial	Fixed 1.32-3ubuntu1.1
	15.10 wily	Ignored end of life
	14.04 LTS trusty	Fixed 1.28-1ubuntu2.1
	12.04 LTS precise	Fixed 1.23-2ubuntu0.1

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libidn	Upstream: ?id=1fb

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-3068-1
Libidn vulnerabilities
24 August 2016