curl (SL7)

Synopsis: Moderate: curl security, bug fix, and enhancement update
Advisory ID: SLSA-2015:2159-6
Issue Date: 2015-11-19
CVE Numbers: CVE-2014-3613

It was found that the libcurl library did not correctly handle partial
literal IP addresses when parsing received HTTP cookies. An attacker able
to trick a user into connecting to a malicious server could use this flaw
to set the user’s cookie to a crafted domain, making other cookie-related
issues easier to exploit. (CVE-2014-3613)

A flaw was found in the way the libcurl library performed the duplication
of connection handles. If an application set the CURLOPT_COPYPOSTFIELDS
option for a handle, using the handle’s duplicate could cause the
application to crash or disclose a portion of its memory. (CVE-2014-3707)

It was discovered that the libcurl library failed to properly handle URLs
with embedded end-of-line characters. An attacker able to make an
application using libcurl access a specially crafted URL via an HTTP proxy
could use this flaw to inject additional headers to the request or
construct additional requests. (CVE-2014-8150)

It was discovered that libcurl implemented aspects of the NTLM and
Negotatiate authentication incorrectly. If an application uses libcurl and
the affected mechanisms in a specifc way, certain requests to a previously
NTLM-authenticated server could appears as sent by the wrong authenticated
user. Additionally, the initial set of credentials for HTTP Negotiate-
authenticated requests could be reused in subsequent requests, although a
different set of credentials was specified. (CVE-2015-3143, CVE-2015-3148)

Bug fixes:

* An out-of-protocol fallback to SSL 3.0 was available with libcurl.
Attackers could abuse the fallback to force downgrade of the SSL version.
The fallback has been removed from libcurl. Users requiring this
functionality can explicitly enable SSL 3.0 through the libcurl API.

* TLS 1.1 and TLS 1.2 are no longer disabled by default in libcurl. You
can explicitly disable them through the libcurl API.

* FTP operations such as downloading files took a significantly long time
to complete. Now, the FTP implementation in libcurl correctly sets
blocking direction and estimated timeout for connections, resulting in
faster FTP transfers.


* With the updated packages, it is possible to explicitly enable or
disable new Advanced Encryption Standard (AES) cipher suites to be used
for the TLS protocol.

* The libcurl library did not implement a non-blocking SSL handshake,
which negatively affected performance of applications based on the libcurl
multi API. The non-blocking SSL handshake has been implemented in libcurl,
and the libcurl multi API now immediately returns the control back to the
application whenever it cannot read or write data from or to the
underlying network socket.

* The libcurl library used an unnecessarily long blocking delay for
actions with no active file descriptors, even for short operations. Some
actions, such as resolving a host name using /etc/hosts, took a long time
to complete. The blocking code in libcurl has been modified so that the
initial delay is short and gradually increases until an event occurs.


– Scientific Linux Development Team