OpenSSL Fixes ECDSA Timing, RNG Fork, and CMS Padding-Oracle Flaws
Vulnerability Disclosure · 18 sources · Updated 2mo ago · First seen Apr 28, 2020
OpenSSL remediated three vulnerabilities: CVE-2019-1547, an ECDSA timing side channel that could expose private keys when applications use explicit EC parameters without a cofactor; CVE-2019-1549, in which OpenSSL 1.1.1–1.1.1c may allow parent and child processes to share RNG state after fork(); and CVE-2019-1563, a Bleichenbacher-style RSA padding oracle in CMS/PKCS#7 decryption. Exploiting the ECDSA and CMS issues requires many observed signature timings or chosen-ciphertext decryption attempts, respectively; normal TLS use through libssl is not affected by CVE-2019-1547.
Upstream fixes are available in OpenSSL 1.1.1d, 1.1.0l, and 1.0.2t, with CVE-2019-1549 fixed in 1.1.1d. Red Hat shipped backported fixes for affected JBoss Core Services Apache HTTP Server packages and RHEL 8 OpenSSL packages, advising customers to restart OpenSSL-linked services or reboot after installation. Slackware also released updated OpenSSL packages for 14.2 and -current. Organizations should patch supported OpenSSL deployments and prioritize review of applications that use explicit EC parameters, CMS/PKCS#7 RSA decryption, or forked processes relying on cryptographic randomness.
