curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. The selected cipher set was stored in a single "static" variable in the library which has the surprising side-effect that if an application sets up multiple concurrent transfers the last one that sets the ciphers will accidentally control the set used by all transfers. In a worst-case scenario this weakens transport security significantly.

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OESA-2021-1216 curl security update

cURL is a computer software project providing a library libcurl and command-line tool curl for transferring data using various protocols. Security Fixes: curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPTSSLCIPHERLIST when...