========================================================================= Ubuntu Security Notice USN-5079-4 September 21, 2021 curl regression ========================================================================= A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 ESM - Ubuntu 14.04 ESM Summary: USN-5079-2 introduced a regression in curl. Software Description: - curl: HTTP, HTTPS, and FTP client and client libraries Details: USN-5079-2 fixed vulnerabilities in curl. One of the fixes introduced a regression. This update fixes the problem. Original advisory details: Patrick Monnerat discovered that curl incorrectly handled upgrades to TLS. When receiving certain responses from servers, curl would continue without TLS even when the option to require a successful upgrade to TLS was specified. (CVE-2021-22946) Patrick Monnerat discovered that curl incorrectly handled responses received before STARTTLS. A remote attacker could possibly use this issue to inject responses and intercept communications. (CVE-2021-22947) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 ESM: curl 7.47.0-1ubuntu2.19+esm2 libcurl3 7.47.0-1ubuntu2.19+esm2 libcurl3-gnutls 7.47.0-1ubuntu2.19+esm2 libcurl3-nss 7.47.0-1ubuntu2.19+esm2 Ubuntu 14.04 ESM: curl 7.35.0-1ubuntu2.20+esm9 libcurl3 7.35.0-1ubuntu2.20+esm9 libcurl3-gnutls 7.35.0-1ubuntu2.20+esm9 libcurl3-nss 7.35.0-1ubuntu2.20+esm9 In general, a standard system update will make all the necessary changes. References: https://ubuntu.com/security/notices/USN-5079-4 https://ubuntu.com/security/notices/USN-5079-1 https://launchpad.net/bugs/1944120