The following was reported by OpenSSL upstream: X509_cmp_time does not properly check the length of the ASN1_TIME string and can read a few bytes out of bounds. In addition, X509_cmp_time accepts an arbitrary number of fractional seconds in the time string. An attacker can use this to craft malformed certificates and CRLs of various sizes and potentially cause a segmentation fault, resulting in a DoS on applications that verify certificates or CRLs. TLS clients that verify CRLs are affected. TLS clients and servers with client authentication enabled may be affected if they use custom verification callbacks. This issue affects all current OpenSSL versions: 1.0.2, 1.0.1, 1.0.0 and 0.9.8. OpenSSL 1.0.2 users should upgrade to 1.0.2b OpenSSL 1.0.1 users should upgrade to 1.0.1n OpenSSL 1.0.0 users should upgrade to 1.0.0s OpenSSL 0.9.8 users should upgrade to 0.9.8zg This issue was reported to OpenSSL on 8th April 2015 by Robert Swiecki (Google), and independently on 11th April 2015 by Hanno Böck. The fix was developed by Emilia Käsper of the OpenSSL development team. Acknowledgements: Red Hat would like to thank the OpenSSL project for reporting this issue.
Created attachment 1035151 [details] Proposed patch for CVE-2015-1789
Public via: https://www.openssl.org/news/secadv_20150611.txt Upstream commits: OpenSSL-1.0.1: https://github.com/openssl/openssl/commit/370ac320301e28bb615cee80124c042649c95d14 OpenSSL-0.9.8: https://github.com/openssl/openssl/commit/fa57f74a3941db6b2efb2f43c6add914ec83db20
Created openssl tracking bugs for this issue: Affects: fedora-all [bug 1231051]
A blog post related to this issue from Hanno Böck, one of the original reporters: https://blog.fuzzing-project.org/15-Out-of-bounds-read-in-OpenSSL-function-X509_cmp_time-CVE-2015-1789-and-other-minor-issues.html It also provides a test case for this issue: https://crashes.fuzzing-project.org/openssl-verify-oob.crt
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 6 Via RHSA-2015:1115 https://rhn.redhat.com/errata/RHSA-2015-1115.html
Statement: (none)
openssl-1.0.1k-10.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
openssl-1.0.1k-10.fc21 has been pushed to the Fedora 21 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 5 Via RHSA-2015:1197 https://rhn.redhat.com/errata/RHSA-2015-1197.html