#VU31950 Out-of-bounds read in macOS - CVE-2016-1839

Vulnerability identifier: #VU31950

Vulnerability risk: Medium

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2016-1839

CWE-ID: CWE-125

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
macOS
Operating systems & Components / Operating system

Vendor: Apple Inc.

Description

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

The vulnerability exists due to a boundary error in The xmlDictAddString function in libxml2 before 2.9.4, as used in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1,. A remote attacker can perform a denial of service (heap-based buffer over-read) via a crafted XML document.

Mitigation
Update to version 10.11.5.

Vulnerable software versions

macOS: 10.11.0 - 10.11.4

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External links
https://lists.apple.com/archives/security-announce/2016/May/msg00001.html
https://lists.apple.com/archives/security-announce/2016/May/msg00002.html
https://lists.apple.com/archives/security-announce/2016/May/msg00003.html
https://lists.apple.com/archives/security-announce/2016/May/msg00004.html
https://rhn.redhat.com/errata/RHSA-2016-2957.html
https://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
https://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html
https://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
https://www.securityfocus.com/bid/90691
https://www.securitytracker.com/id/1035890
https://www.securitytracker.com/id/1038623
https://www.ubuntu.com/usn/USN-2994-1
https://xmlsoft.org/news.html
https://access.redhat.com/errata/RHSA-2016:1292
https://bugzilla.gnome.org/show_bug.cgi?id=758605
https://git.gnome.org/browse/libxml2/commit/?id=a820dbeac29d330bae4be05d9ecd939ad6b4aa33
https://kc.mcafee.com/corporate/index?page=content&id=SB10170
https://security.gentoo.org/glsa/201701-37
https://support.apple.com/HT206564
https://support.apple.com/HT206566
https://support.apple.com/HT206567
https://support.apple.com/HT206568
https://www.debian.org/security/2016/dsa-3593
https://www.tenable.com/security/tns-2016-18

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.