New release of OpenSSL [1] fixes the following: By using non-DER or invalid encodings outside the signed portion of a certificate the fingerprint can be changed without breaking the signature. Although no details of the signed portion of the certificate can be changed this can cause problems with some applications: e.g. those using the certificate fingerprint for blacklists. 1. Reject signatures with non zero unused bits. If the BIT STRING containing the signature has non zero unused bits reject the signature. All current signature algorithms require zero unused bits. 2. Check certificate algorithm consistency. Check the AlgorithmIdentifier inside TBS matches the one in the certificate signature. NB: this will result in signature failure errors for some broken certificates. 3. Check DSA/ECDSA signatures use DER. Reencode DSA/ECDSA signatures and compare with the original received signature. Return an error if there is a mismatch. This will reject various cases including garbage after signature (thanks to Antti Karjalainen and Tuomo Untinen from the Codenomicon CROSS program for discovering this case) and use of BER or invalid ASN.1 INTEGERs (negative or with leading zeroes). Upstream patches: - master: https://github.com/openssl/openssl/commit/684400ce192dac51df3d3e92b61830a6ef90be3e - 0.9.8: https://github.com/openssl/openssl/commit/ec2fede9467ae1a65f452d3a39f7fbc4891d9285 - 1.0.1: https://github.com/openssl/openssl/commit/a8565530e27718760220df469f0a071c85b9e731 There was also an additional fix for this: - https://github.com/openssl/openssl/commit/cb62ab4b17818fe66d2fed0a7fe71969131c811b [1]: https://www.openssl.org/news/changelog.html
External References: https://www.openssl.org/news/secadv_20150108.txt
openssl-1.0.1e-41.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Via RHSA-2015:0066 https://rhn.redhat.com/errata/RHSA-2015-0066.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 5 Via RHSA-2015:0800 https://rhn.redhat.com/errata/RHSA-2015-0800.html
Statement: This issue affects the version of openssl098e as shipped with Red Hat Enterprise Linux 6 and 7. Red Hat Product Security has rated this issue as having Low security impact and does not plan to address this flaw for the above components in any future security updates. This issue affects the version of openssl097a as shipped with Red Hat Enterprise Linux 5. Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.