#VU33781 Input validation error in Emacs - CVE-2017-14482

Vulnerability identifier: #VU33781

Vulnerability risk: High

CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2017-14482

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Emacs
Client/Desktop applications / Office applications

Vendor: GNU

Description

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

GNU Emacs before 25.3 allows remote attackers to execute arbitrary code via email with crafted "Content-Type: text/enriched" data containing an x-display XML element that specifies execution of shell commands, related to an unsafe text/enriched extension in lisp/textmodes/enriched.el, and unsafe Gnus support for enriched and richtext inline MIME objects in lisp/gnus/mm-view.el. In particular, an Emacs user can be instantly compromised by reading a crafted email message (or Usenet news article).

Mitigation
Install update from vendor's website.

Vulnerable software versions

Emacs: 25.1 - 25.2

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External links
https://www.debian.org/security/2017/dsa-3975
https://www.openwall.com/lists/oss-security/2017/09/11/1
https://access.redhat.com/errata/RHSA-2017:2771
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=28350
https://git.savannah.gnu.org/cgit/emacs.git/commit/?h=emacs-25&id=9ad0fcc54442a9a01d41be19880250783426db70
https://security.gentoo.org/glsa/201801-07
https://www.debian.org/security/2017/dsa-3970
https://www.gnu.org/software/emacs/index.html#Releases

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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.