Microsoft Security Advisory (961509): Research proves feasibility of collision attack
Revision Note: Advisory published Advisory Summary:Microsoft is aware that research was published at a security conference proving a successful attack against X.509 digital certificates signed using the MD5 hashing algorithm. This attack method would allow an attacker to generate additional digital certificates with different content that have the same digital signature as an original certificate. The MD5 algorithm had previously shown a vulnerability, but a practical attack had not yet been demonstrated.
MAC_SEEOTHERUIDS(4) BSD Kernel Interfaces Manual MAC_SEEOTHERUIDS(4)NAME
mac_seeotheruids -- simple policy controlling whether users see other users
SYNOPSIS
To compile the policy into your kernel, place the following lines in your kernel configuration file:
options MAC
options MAC_SEEOTHERUIDS
Alternately, to load the module at boot time, place the following line in your kernel configuration file:
options MAC
and in loader.conf(5):
mac_seeotheruids_load="YES"
DESCRIPTION
The mac_seeotheruids policy module, when enabled, denies users to see processes or sockets owned by other users.
To enable mac_seeotheruids, set the sysctl OID security.mac.seeotheruids.enabled to 1. To permit superuser awareness of other credentials by
virtue of privilege, set the sysctl OID security.mac.seeotheruids.suser_privileged to 1.
To allow users to see processes and sockets owned by the same primary group, set the sysctl OID
security.mac.seeotheruids.primarygroup_enabled to 1.
To allow processes with a specific group ID to be exempt from the policy, set the sysctl OID security.mac.seeotheruids.specificgid_enabled to
1, and security.mac.seeotheruids.specificgid to the group ID to be exempted.
Label Format
No labels are defined for mac_seeotheruids.
SEE ALSO mac(4), mac_biba(4), mac_bsdextended(4), mac_ifoff(4), mac_lomac(4), mac_mls(4), mac_none(4), mac_partition(4), mac_portacl(4), mac_test(4),
mac(9)HISTORY
The mac_seeotheruids policy module first appeared in FreeBSD 5.0 and was developed by the TrustedBSD Project.
AUTHORS
This software was contributed to the FreeBSD Project by Network Associates Labs, the Security Research Division of Network Associates Inc.
under DARPA/SPAWAR contract N66001-01-C-8035 (``CBOSS''), as part of the DARPA CHATS research program.
BUGS
See mac(9) concerning appropriateness for production use. The TrustedBSD MAC Framework is considered experimental in FreeBSD.
While the MAC Framework design is intended to support the containment of the root user, not all attack channels are currently protected by
entry point checks. As such, MAC Framework policies should not be relied on, in isolation, to protect against a malicious privileged user.
BSD October 6, 2005 BSD