The char_buffer_read function in the mod_ssl module for Apache 2.x, when using reverse proxying to an SSL server, allows remote attackers to cause a denial of service (segmentation fault).
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11864
https://exchange.xforce.ibmcloud.com/vulnerabilities/17273
http://www.redhat.com/support/errata/RHSA-2004-463.html