The curl packages provide the libcurl library and the curl utility for downloading files from servers using various protocols, including HTTP, FTP, and LDAP. 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. 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. 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. 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. Red Hat would like to thank the cURL project for reporting these issues. 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. Enhancements: * With the updated packages, it is possible to explicitly enable or disable new Advanced Encryption Standard 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. All curl users are advised to upgrade to these updated packages, which contain backported patches to correct these issues and add these enhancements.