CVE-2021-22898: Infoleak

A vulnerability was found in curl where, due to flaw in the option parser for sending NEWENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server. Therefore potentially revealing sensitive internal information to the server using a clear-text network protocol.

— Red Hat

curl 7.7 through 7.76.1 suffers from an information disclosure when the -t command line option, known as CURLOPTTELNETOPTIONS in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEWENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol.

cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a flaw in the option parser for sending NEWENV variables. By sending a specially-crafted request using a clear-text network protocol, an attacker could exploit this vulnerability to obtain sensitive internal information to the server, and use this information to launch further attacks against the affected system.

— IBM