Vulnerability identifier: #VU33070

Vulnerability risk: Medium

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

CVE-ID: CVE-2016-3739

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
cURL
Client/Desktop applications / Other client software

Vendor: curl.haxx.se

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

The (1) mbed_connect_step1 function in lib/vtls/mbedtls.c and (2) polarssl_connect_step1 function in lib/vtls/polarssl.c in cURL and libcurl before 7.49.0, when using SSLv3 or making a TLS connection to a URL that uses a numerical IP address, allow remote attackers to spoof servers via an arbitrary valid certificate.

Mitigation
Install update from vendor's website.

Vulnerable software versions

cURL: 7.1 - 7.48.0

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External links
http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
http://www.securityfocus.com/bid/90726
http://www.securitytracker.com/id/1035907
http://www.slackware.com/security/viewer.php?l=slackware-security&y=2016&m=slackware-security.495349
http://curl.haxx.se/changes.html#7_49_0
http://curl.haxx.se/CVE-2016-3739.patch
http://curl.haxx.se/docs/adv_20160518.html
http://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149
http://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722
http://security.gentoo.org/glsa/201701-47

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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.