cURL and libcurl 7.18.0 through 7.32.0, when built with OpenSSL, disables the certificate CN and SAN name field verification (CURLOPTSSLVERIFYHOST) when the digital signature verification (CURLOPTSSLVERIFYPEER) is disabled, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

Heap-based buffer overflow in the curleasyunescape function in lib/escape.c in cURL and libcurl 7.7 through 7.30.0 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted string ending in a "%" (percent) character.

A security flaw was found in the way the library of cURL, an utility for retrieval of files from remote servers, performed match of cookie domain names when making a decision if (previously stored cookies) should be sent to particular domain. Due to a bug in match function implementation, (formerly) the decision / match succeeded also in cases, where just suffix / certain part of the domain name matched the domain name, the current request originated from. A remote attacker could use this flaw to possibly hijack the user session of the victim by submitting a request containing a specially-crafted domain name.

References: [1] http://thread.gmane.org/gmane.comp.web.curl.library/38986

Acknowledgements:

Red Hat would like to thank the cURL project for reporting this issue. Upstream acknowledges YAMADA Yasuharu as the original reporter.

CRLF injection vulnerability in libcurl 6.0 through 7.x before 7.40.0, when using an HTTP proxy, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via CRLF sequences in a URL.

The curleasyduphandle function in libcurl 7.17.1 through 7.38.0, when running with the CURLOPTCOPYPOSTFIELDS option, does not properly copy HTTP POST data for an easy handle, which triggers an out-of-bounds read that allows remote web servers to read sensitive memory information.

cURL and libcurl 7.10.6 through 7.41.0 does not properly re-use NTLM connections, which allows remote attackers to connect as other users via an unauthenticated request, a similar issue to CVE-2014-0015.

cURL and libcurl 7.10.6 through 7.41.0 do not properly re-use authenticated Negotiate connections, which allows remote attackers to connect as other users via a request.

A flaw was found in libcurl from versions 7.29.0 through 7.71.1. An application that performs multiple requests with libcurl's multi API, and sets the CURLOPTCONNECTONLY option, might experience libcurl using the wrong connection. The highest threat from this vulnerability is to data confidentiality.