CVE-2016-3739 Security feature bypass in n/a

Medium 5.3 Published Updated

Attackers can spoof servers using valid certificates when cURL connects to IP addresses via SSLv3 or TLS, bypassing certificate validation.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2016-3739?

CVE-2016-3739 is a medium-severity vulnerability in Haxx Curl, published on 20 May 2016. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-20

Which versions are affected by CVE-2016-3739?

It affects 1 product.

Products include Haxx Curl.

How do I fix CVE-2016-3739?

Upgrade to a fixed version.

Is CVE-2016-3739 being exploited?

There is no known exploitation of CVE-2016-3739 in the wild and no public exploit code.

All Haxx Curl vulnerabilities

Sources

Also known as CURL-CVE-2016-3739, DEBIAN-CVE-2016-3739, GHSA-4rcg-2r46-4hcc.

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