Arch Linux Security Advisory ASA-202106-6 ========================================= Severity: High Date : 2021-06-01 CVE-ID : CVE-2021-22898 CVE-2021-22901 Package : libcurl-compat Type : multiple issues Remote : Yes Link : https://security.archlinux.org/AVG-1997 Summary ======= The package libcurl-compat before version 7.77.0-1 is vulnerable to multiple issues including arbitrary code execution and information disclosure. Resolution ========== Upgrade to 7.77.0-1. # pacman -Syu "libcurl-compat>=7.77.0-1" The problems have been fixed upstream in version 7.77.0. Workaround ========== - CVE-2021-22898 can be mitigated by avoiding to use the -t command line option and CURLOPT_TELNETOPTIONS. - No known workaround exists for CVE-2021-22901. Description =========== - CVE-2021-22898 (information disclosure) A security issue has been found in curl before version 7.77.0. curl supports the -t command line option, known as CURLOPT_TELNETOPTIONS in libcurl. This rarely used option is used to send variable=content pairs to TELNET servers. Due to flaw in the option parser for sending NEW_ENV 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. - CVE-2021-22901 (arbitrary code execution) libcurl before version 7.77.0 can be tricked into using already freed memory when a new TLS session is negotiated or a client certificate is requested on an existing connection. For example, this can happen when a TLS server requests a client certificate on a connection that was established without one. A malicious server can use this in rare unfortunate circumstances to potentially reach remote code execution in the client. The flaw can only happen in libcurl built to use OpenSSL. Impact ====== curl could disclose potentially sensitive memory information to a remote server over Telnet when an uncommon option is used. Additionally, a remote attacker could cause arbitrary code execution through a crafted TLS handshake. References ========== https://curl.se/docs/CVE-2021-22898.html https://github.com/curl/curl/commit/39ce47f219b09c380b81f89fe54ac586c8db6bde https://curl.se/docs/CVE-2021-22901.html https://github.com/curl/curl/commit/7f4a9a9b2a49547eae24d2e19bc5c346e9026479 https://security.archlinux.org/CVE-2021-22898 https://security.archlinux.org/CVE-2021-22901