Vulnerability identifier: #VU82525

Vulnerability risk: Medium

CVSSv3.1: 6.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2013-7439

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libx11
Other software / Other software solutions

Vendor:

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to multiple off-by-one errors in the MakeBigReq and SetReqLen macros in include/X11/Xlibint.h in X11R6.x and libX11. A remote attacker can create a specially crafted request, trigger buffer overflow and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://lists.x.org/archives/xorg-announce/2015-April/002561.html
http://seclists.org/oss-sec/2015/q2/81
http://www.debian.org/security/2015/dsa-3224
http://www.oracle.com/technetwork/topics/security/bulletinjul2015-2511963.html
http://www.securityfocus.com/bid/73962
http://www.ubuntu.com/usn/USN-2568-1
http://bugs.freedesktop.org/show_bug.cgi?id=56508

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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.