Vulnerability identifier: #VU32226

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-7942

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libx11
Other software / Other software solutions

Vendor: xorg.freedesktop.org

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

The XGetImage function in X.org libX11 before 1.6.4 might allow remote X servers to gain privileges via vectors involving image type and geometry, which triggers out-of-bounds read operations.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libx11: 1.6.0 - 1.6.3

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External links
http://www.openwall.com/lists/oss-security/2016/10/04/2
http://www.openwall.com/lists/oss-security/2016/10/04/4
http://www.securityfocus.com/bid/93363
http://www.securitytracker.com/id/1036945
http://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=8ea762f94f4c942d898fdeb590a1630c83235c17
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GMCVDXMFPXR7QGMKDG22WPPJCXH2X3L7/
http://lists.x.org/archives/xorg-announce/2016-October/002720.html
http://security.gentoo.org/glsa/201704-03
http://usn.ubuntu.com/3758-1/
http://usn.ubuntu.com/3758-2/

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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.