CVE-2016-7055

OpenSSL Security Advisory [10 Nov 2016] ======================================== ChaCha20/Poly1305 heap-buffer-overflow (CVE-2016-7054) ====================================================== Severity: High TLS connections using *-CHACHA20-POLY1305 ciphersuites are susceptible to a DoS attack by corrupting larger payloads. This can result in an OpenSSL crash. This issue is not considered to be exploitable beyond a DoS. OpenSSL 1.1.0 users should upgrade to 1.1.0c This issue does not affect OpenSSL versions prior to 1.1.0 This issue was reported to OpenSSL on 25th September 2016 by Robert Święcki (Google Security Team), and was found using honggfuzz. The fix was developed by Richard Levitte of the OpenSSL development team. CMS Null dereference (CVE-2016-7053) ==================================== Severity: Moderate Applications parsing invalid CMS structures can crash with a NULL pointer dereference. This is caused by a bug in the handling of the ASN.1 CHOICE type in OpenSSL 1.1.0 which can result in a NULL value being passed to the structure callback if an attempt is made to free certain invalid encodings. Only CHOICE structures using a callback which do not handle NULL value are affected. OpenSSL 1.1.0 users should upgrade to 1.1.0c This issue does not affect OpenSSL versions prior to 1.1.0 This issue was reported to OpenSSL on 12th October 2016 by Tyler Nighswander of ForAllSecure. The fix was developed by Stephen Henson of the OpenSSL development team. Montgomery multiplication may produce incorrect results (CVE-2016-7055) ======================================================================= Severity: Low There is a carry propagating bug in the Broadwell-specific Montgomery multiplication procedure that handles input lengths divisible by, but longer than 256 bits. Analysis suggests that attacks against RSA, DSA and DH private keys are impossible. This is because the subroutine in question is not used in operations with the private key itself and an input of the attacker’s direct choice. Otherwise the bug can manifest itself as transient authentication and key negotiation failures or reproducible erroneous outcome of public-key operations with specially crafted input. Among EC algorithms only Brainpool P-512 curves are affected and one presumably can attack ECDH key negotiation. Impact was not analyzed in detail, because pre-requisites for attack are considered unlikely. Namely multiple clients have to choose the curve in question and the server has to share the private key among them, neither of which is default behaviour. Even then only clients that chose the curve will be affected. OpenSSL 1.1.0 users should upgrade to 1.1.0c This issue does not affect OpenSSL versions prior to 1.0.2. Due to the low severity of this defect we are not issuing a new 1.0.2 release at this time. We recommend that 1.0.2 users wait for the next 1.0.2 release for the fix to become available. The fix is also available in the OpenSSL git repository in commit 57c4b9f6a2. This issue was publicly reported as transient failures and was not initially recognized as a security issue. Thanks to Richard Morgan for providing reproducible case. The fix was developed by Andy Polyakov of the OpenSSL development team. Note ==== As per our previous announcements and our Release Strategy (https://www.openssl.org/policies/releasestrat.html), support for OpenSSL version 1.0.1 will cease on 31st December 2016. No security updates for that version will be provided after that date. Users of 1.0.1 are advised to upgrade. Support for versions 0.9.8 and 1.0.0 ended on 31st December 2015. Those versions are no longer receiving security updates. References ========== URL for this Security Advisory: https://www.openssl.org/news/secadv/20161110.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