Vulnerability identifier: #VU1432

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-9963

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Exim
Server applications / Mail servers

Vendor: Exim

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information.

The vulnerability exists due to usage of incorrect buffer when displaying error message for DATA command in src/src/transports/smtp.c file. A remote unauthenticated attacker can send a specially crafted SMTP command and obtain potentially sensitive information, such as DKIM key.

Mitigation
Install the latest version 4.87.1 or 4.88, which fixes this vulnerability.

Vulnerable software versions

Exim: 4.69 - 4.87

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External links
http://bugs.exim.org/show_bug.cgi?id=1996
http://seclists.org/oss-sec/2016/q4/693
http://www.exim.org/static/doc/CVE-2016-9963.txt

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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.