Arch Linux Security Advisory ASA-201906-7 ========================================= Severity: Low Date : 2019-06-11 CVE-ID : CVE-2019-1543 Package : openssl Type : information disclosure Remote : Yes Link : https://security.archlinux.org/AVG-919 Summary ======= The package openssl before version 1.1.1.c-1 is vulnerable to information disclosure. Resolution ========== Upgrade to 1.1.1.c-1. # pacman -Syu "openssl>=1.1.1.c-1" The problem has been fixed upstream in version 1.1.1.c. Workaround ========== None. Description =========== An issue has been found in OpenSSL <= 1.1.1b, where an application using ChaCha20-Poly1305 could set a non-default nonce length to be longer than 12 bytes and then mistakenly reuse a nonce. ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for every encryption operation. RFC 7539 specifies that the nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and front pads the nonce with 0 bytes if it is less than 12 bytes. However it also incorrectly allows a nonce to be set of up to 16 bytes. In this case only the last 12 bytes are significant and any additional leading bytes are ignored. Impact ====== A remote attacker could disclose sensitive information via an invalid nonce. References ========== https://www.openssl.org/news/secadv/20190306.txt https://github.com/openssl/openssl/commit/f426625b6a https://security.archlinux.org/CVE-2019-1543