-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 OpenSSL Security Advisory [10 September 2019] ============================================= ECDSA remote timing attack (CVE-2019-1547) ========================================== Severity: Low Normally in OpenSSL EC groups always have a co-factor present and this is used in side channel resistant code paths. However, in some cases, it is possible to construct a group using explicit parameters (instead of using a named curve). In those cases it is possible that such a group does not have the cofactor present. This can occur even where all the parameters match a known named curve. If such a curve is used then OpenSSL falls back to non-side channel resistant code paths which may result in full key recovery during an ECDSA signature operation. In order to be vulnerable an attacker would have to have the ability to time the creation of a large number of signatures where explicit parameters with no co-factor present are in use by an application using libcrypto. For the avoidance of doubt libssl is not vulnerable because explicit parameters are never used. OpenSSL versions 1.1.1, 1.1.0 and 1.0.2 are affected by this issue. OpenSSL 1.1.1 users should upgrade to 1.1.1d OpenSSL 1.1.0 users should upgrade to 1.1.0l OpenSSL 1.0.2 users should upgrade to 1.0.2t This issue was reported by Cesar Pereida García, Sohaib ul Hassan, Nicola Tuveri, Iaroslav Gridin, Alejandro Cabrera Aldaya, and Billy Brumley. The fix was developed by Billy Brumley. It was reported to OpenSSL on 5th August 2019. Fork Protection (CVE-2019-1549) =============================== Severity: Low OpenSSL 1.1.1 introduced a rewritten random number generator (RNG). This was intended to include protection in the event of a fork() system call in order to ensure that the parent and child processes did not share the same RNG state. However this protection was not being used in the default case. A partial mitigation for this issue is that the output from a high precision timer is mixed into the RNG state so the likelihood of a parent and child process sharing state is significantly reduced. If an application already calls OPENSSL_init_crypto() explicitly using OPENSSL_INIT_ATFORK then this problem does not occur at all. OpenSSL version 1.1.1 is affected by this issue. OpenSSL 1.1.1 users should upgrade to 1.1.1d This issue was reported by Matt Caswell. The fix was developed by Matthias St. Pierre. It was reported to OpenSSL on 27th May 2019. Padding Oracle in PKCS7_dataDecode and CMS_decrypt_set1_pkey (CVE-2019-1563) ============================================================================ Severity: Low In situations where an attacker receives automated notification of the success or failure of a decryption attempt an attacker, after sending a very large number of messages to be decrypted, can recover a CMS/PKCS7 transported encryption key or decrypt any RSA encrypted message that was encrypted with the public RSA key, using a Bleichenbacher padding oracle attack. Applications are not affected if they use a certificate together with the private RSA key to the CMS_decrypt or PKCS7_decrypt functions to select the correct recipient info to decrypt. OpenSSL 1.1.1 users should upgrade to 1.1.1d OpenSSL 1.1.0 users should upgrade to 1.1.0l OpenSSL 1.0.2 users should upgrade to 1.0.2t This issue was reported by and the fix developed by Bernd Edlinger. It was reported to OpenSSL on 21st August 2019. Note ===== OpenSSL 1.0.2 is currently only receiving security updates. Support for 1.0.2 will end on 31st December 2019. Support for 1.1.0 ends on 11th September 2019 so 1.1.0l is expected to be the last 1.1.0 release. Users of these versions should upgrade to OpenSSL 1.1.1. References ========== URL for this Security Advisory: https://www.openssl.org/news/secadv/20190910.txt Note: the online version of the advisory may be updated with additional details over time. For details of OpenSSL severity classifications please see: https://www.openssl.org/policies/secpolicy.html -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhlersmDwVrHlGQg52cTSbQ5gRJEFAl13vK0ACgkQ2cTSbQ5g RJGJIgf+Me900bLV9TrVDWvNRQbuRe0tOPPhP59J4tJAJiRZ1GG0JV2YITQynjTP hrz9mvajgWbkGYlTZmPVFOdJr7LKbrUrxk7shEfXqmiiCLG8tHYiCe3PF+/Cy7gA X1vY9CDfv//3VSqOLM9RM3CCcWAAv3KeP851X0PgCiMVvGAJbYOu3bmB+KsEKFzm fWRDabUMbl1KCSgCIvvlNv0bKR/GfpW3cWruUvG0sfjyPWwS+yn8z0T3/ibFJqkb Cmuqa3/kC9uZg8AhiODR+nz6D1mC2UiNZ2Wa/XO6O68rO/y3ZKbaiMGLze1qJep5 3PnybOw8b3JvpVRFYw09YwgLObBX8w== =8bP1 -----END PGP SIGNATURE-----
