Fix IAKERB context aliasing bugs [CVE-2015-2696] The IAKERB mechanism currently replaces its context handle with the krb5 mechanism handle upon establishment, under the assumption that most GSS functions are only called after context establishment. This assumption is incorrect, and can lead to aliasing violations for some programs. Maintain the IAKERB context structure after context establishment and add new IAKERB entry points to refer to it with that type. Add initiate and established flags to the IAKERB context structure for use in gss_inquire_context() prior to context establishment. CVE-2015-2696: In MIT krb5 1.9 and later, applications which call gss_inquire_context() on a partially-established IAKERB context can cause the GSS-API library to read from a pointer using the wrong type, generally causing a process crash. Java server applications using the native JGSS provider are vulnerable to this bug. A carefully crafted IAKERB packet might allow the gss_inquire_context() call to succeed with attacker-determined results, but applications should not make access control decisions based on gss_inquire_context() results prior to context establishment. CVSSv2 Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C/E:POC/RL:OF/RC:C [ghudson@mit.edu: several bugfixes, style changes, and edge-case behavior changes; commit message and CVE description] (cherry picked from commit e04f0283516e80d2f93366e0d479d13c9b5c8c2a) https://github.com/krb5/krb5/commit/096cfaa18504d20889a3d8829decb1bf72dd0ac5 Author: Nicolas Williams Committer: Tom Yu Commit: 096cfaa18504d20889a3d8829decb1bf72dd0ac5 Branch: krb5-1.14 src/lib/gssapi/krb5/gssapiP_krb5.h | 114 ++++++++++++ src/lib/gssapi/krb5/gssapi_krb5.c | 105 ++++++++++-- src/lib/gssapi/krb5/iakerb.c | 351 +++++++++++++++++++++++++++++++++--- 3 files changed, 529 insertions(+), 41 deletions(-)