CVE-2016-3739

Severity: medium (CVSS 5.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 6.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2016-05-20 · updated 2026-06-17
Weakness: CWE-20

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.

Affected products

curl: 7.21.0, 7.21.1, 7.21.2, 7.21.3, 7.21.4, 7.21.5 (+31)

References

http://www.openwall.com/lists/oss-security/2024/03/27/4
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
https://curl.haxx.se/CVE-2016-3739.patch
https://curl.haxx.se/changes.html#7_49_0
https://curl.haxx.se/docs/adv_20160518.html
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722
https://security.gentoo.org/glsa/201701-47
http://www.openwall.com/lists/oss-security/2024/03/27/4

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